Abstract: A wash optimization system and related methods are provided that increase the efficiency and the effectiveness of engine washes. A system comprising at least one processor receives sensor data representing one or more measured parameters of a turbine engine and determines at least one performance parameter based on the sensor data. The at least one performance parameter represents one or more particulate values associated with the turbine engine. The system generates a health state for the turbine engine based on the at least one performance parameter and generates a wash identifier based on the health state of the turbine engine.

Abstract: A fuel and emissions control method for an internal combustion engine of a vehicle includes performing passive evaluation of individual cylinder fuel control (ICFC) multipliers by determining whether any of the ICFC multipliers exceed an ICFC multiplier threshold and, in response, determining first and second cylinder fuel-air (FA) imbalances during first and second passive evaluation stages, respectively, separated by a passive evaluation delay period, and based on a comparison between the first and second cylinder FA imbalances, either (i) passing, by the controller, the evaluation and maintaining, by the controller, the ICFC multipliers or (ii) failing, by the controller, the evaluation and (a) resetting, by the controller, the ICFC multipliers and (b) increasing, by the controller, the passive evaluation delay period and repeating the passive evaluation.

Abstract: A method for monitoring a secondary airflow (SAIR) system in an engine includes determining degradation of the SAIR system adding a SAIR to downstream of an engine cylinder exhaust based on a comparison of the SAIR before and after a shutdown of a SAIR pump, the SAIR calculated from a fuel injection amount, an exhaust air-fuel ratio, and an engine intake airflow. In this way, SAIR at the exhaust manifold can be monitored utilizing existing onboard sensors and technology, thereby maintaining OBD and emissions monitoring, reducing engine emissions, and maintaining costs.

Abstract: A method and system is provided for correcting fueling commands. For example, the method and system may calibrate an engine operating in a steady-state mode by determining a plurality of accuracy errors associated with a fueling rate based on a plurality of sensor measurements. The method and system may determine fueling rate correction data during on-line operation of the engine based on the plurality of accuracy errors. The on-line operation of the engine may comprise operating the engine in a transient mode at a first period of time and a steady-state mode at a second period of time. The method and system may control at least one fueling valve during operation of the engine using a corrected fueling command. The corrected fueling command is based on the fueling rate correction data.

Abstract: A method for ascertaining a variable characterizing a flow rate of a fuel injector during an operation of an internal combustion engine, to which the fuel injector is assigned. At least two input values for a data-based model are ascertained, and at least one output value is determined with the aid of the data-based model, on the basis of which a value for the variable characterizing the flow rate of the fuel injector is ascertained. The data-based model combines at least two methods differing from one another for ascertaining a variable characterizing a flow rate of a fuel injector.

Abstract: A method of operating a dual fuel engine includes conveying intake air, and a first fuel as a vapor and as a liquid, into a combustion cylinder in an engine, and directly injecting a second fuel into the combustion cylinder to form a first combustion charge of the first fuel as a vapor and as a liquid, the second fuel, and intake air. The second fuel is ignited to initiate combustion of the first combustion charge. Operating the dual fuel engine further includes varying at least one of, a vapor proportion of the first fuel or a total proportion of the first fuel, in a subsequent combustion charge to mitigate undesired combustion. The first fuel can include a liquid alcohol fuel. The second fuel can include a liquid compression-ignition fuel. Related apparatus and control logic is also disclosed.

Abstract: A control apparatus for a fuel supply apparatus is used in an engine system. The engine system includes an engine including a fuel injection valve, and the fuel supply apparatus including a fuel pump configured to supply fuel in a fuel tank to a supply pipe connected to the fuel injection valve, and a relief valve provided in the supply pipe. The control apparatus for the fuel supply apparatus includes an executor configured to execute, when the fuel is supplied to the fuel tank, relief pressure control for driving the fuel pump to open the relief valve until a predetermined termination condition is satisfied.

Abstract: A method of compensating fuel for each cylinder of an engine during purging may include, compensating a fuel injection time for each cylinder depending on an amount of intake air for each cylinder, an injection pressure of the injector, and an internal pressure of a combustion chamber of the engine; pressurizing a vaporized gas adsorbed into a canister and injecting the pressurized vaporized gas into the intake pipe by operating an active purge pump; and estimating an amount of vaporized gas reaching each combustion chamber and converting the fuel injection time depending on the estimated amount of vaporized gas.

Abstract: An air-fuel ratio control system (1) including an air-fuel ratio control section (3) for controlling the air-fuel ratio ? of an air-fuel mixture, an exhaust gas purifier (4); an air-fuel ratio sensor (5) whose output changes sharply when ? in the exhaust gas changes between rich and lean sides about a stoichiometric air-fuel ratio; a heater (6); and a temperature control section (7). The air-fuel ratio control section (3) controls ? based on the output of the air-fuel ratio sensor (5) using, as a target air-fuel ratio, a predetermined air-fuel ratio such that 0.980??<1.000 is satisfied, and when a change amount ?? ? is 0.008, an output difference ?V is 150 mV or smaller. The temperature control section (7) controls the temperature of the air-fuel ratio sensor (5) to a predetermined target temperature of 650° C. or higher.

Abstract: A mixed fuel amount control system applying active purging includes: a fuel tank in which biofuel and fossil fuel are mixed and stored, an active purging device to supply an evaporated gas evaporated in the fuel tank to an intake pipe, and a concentration sensor to sense a mixing ratio of the biofuel stored in the fuel tank changes. In particular, the flow rate and the concentration of the evaporated gas of the fuel tank flowing into the intake pipe are changed according to a mixing ratio of biofuel and fossil fuel.

Abstract: A system for control of an internal combustion system having subsystems, each with different response times. Subsystems may include a fuel system, an air handling system, and an aftertreatment system, each being operated in response to a set of reference values generated by a respective target determiner. Calibration of each subsystem may be performed independently. The fuel system is controlled at a first time constant. The air handling system is controlled on the order of a second time constant slower than the first time constant. The aftertreatment system is controlled on the order of a third time constant slower than the second time constant. A subsystem manager is optionally in operative communication with each target determiner to coordinate control. Generally, dynamic parameters from slower subsystems are treated as static parameters when determining reference values for controlling a faster subsystem.

Abstract: The method for calculating the fuel injection amount of a fuel vapor dual purge system may include the steps of calculating, by a controller, volumetric efficiency of a combustion chamber, determining, by the controller, a fuel vapor detection delay time at which the fuel vapor is detected in a surge tank according to the calculated volumetric efficiency of a combustion chamber, calculating, by the controller, a time at which the fuel vapor is injected into the combustion chamber based on the determined fuel vapor detection delay time, and calculating, by the controller, a fuel vapor total injection amount at the time at which the fuel vapor is injected into the combustion chamber. The method may be performed in a turbocharger operation section.

Abstract: A method for dynamic gas partial pressure correction of an internal combustion engine with external mixture formation. A mixture formation is carried out in an intake manifold upstream of the cylinder of the internal combustion engine, and in which in addition to the gas partial pressure of the fresh air flowing continuously into the intake manifold, the gas partial pressure of the fuel, fed discontinuously into the intake manifold, is also taken into account. The gas partial pressure of the fuel, fed into the intake manifold, said pressure which is assumed to be stationary as a function of determined parameters, is dynamically adjusted for each of the cylinder-individual, temporally successive injections, discharged into the intake manifold, by means of a correction factor and a fresh air correction filling value.

Abstract: A control device includes a target value acquisition portion configured to acquire a target value of amount of control per predetermined computation cycle, a control portion configured to control the control target using the acquired target value, a target smoothing value calculation portion configured to calculate a target smoothing value in which a temporal change in the target value is slowed down, and a state determination portion configured to calculate a first difference that is a difference between the target value and the target smoothing value to determine that the amount of control is in a transient state when the calculated first difference is equal to or more than a predetermined first threshold value and to determine that the amount of control is in a non-transient state when the first difference is smaller than the first threshold value.

Abstract: A control device for an internal combustion engine includes processing circuitry. The processing circuitry is configured to execute a purging process that draws the fuel vapor trapped in the canister into the intake passage by controlling the purge valve, a fuel feeding process that feeds the air-fuel mixture, which includes the fuel supplied to the cylinder, to the exhaust passage without burning the air-fuel mixture in the cylinder, and a fuel supply process that supplies fuel to the cylinder when the fuel feeding process is being performed. The processing circuitry is further configured to perform the fuel supply process by performing the purging process.

Abstract: When a purge valve opens, a CPU calculates a purge concentration learning value based on an air-fuel ratio detected by an air-fuel ratio sensor. Additionally, under the condition that a temperature increase request of a three-way catalyst is generated, the CPU performs dither control that sets one of a plurality of cylinders as a rich combustion cylinder, which is richer than a theoretical air-fuel ratio, and the remaining cylinders as lean combustion cylinders, which are leaner than the theoretical air-fuel ratio. When the dither control is performed, the CPU forbids the update of the purge concentration learning value.

Abstract: A control parameter computation method includes, by a processor, identifying, for each time segment, a plurality of mathematical models of different structures. The method also includes, computing an adaptiveness representing a level of adaptation between a time series of the computed control variable predicted values and time series data of the control variable in the paired data corresponding to the time segments different from the time segment employed in the identification. The method also includes, selecting, as a mathematical model for the paired data of the time segment. The method also includes, configuring a PID controller, generating a transfer function represented by a product of the PID controller and the selected mathematical model, and generating a function representing a gain margin of the transfer function and a function representing a phase margin of the transfer function. The method also includes computing a parameter Lambda.

Abstract: A method for operating an engine system including an internal combustion engine and an exhaust gas aftertreatment device, including: carrying out a fill level control to control a fill level of the exhaust gas aftertreatment device as a function of a predefined fill level setpoint value; operating a pilot control for the fill level control; and adapting the pilot control as a function of a deviation between a measured lambda value and a modeled lambda value.

Abstract: An abnormality detection device for an air-fuel ratio sensor is provided. An air-fuel ratio sensor is provided in an exhaust passage. A storage device stores mapping data specifying a mapping. The mapping outputs an abnormality determination variable using first time series data and second time series data as an input. The first time series data is time series data of an excess amount variable in a first predetermined period. The excess amount variable is a variable corresponding to an excess amount of fuel actually discharged to the exhaust passage in relation to an amount of fuel reacting without excess or deficiency with oxygen contained in a fluid discharged to the exhaust passage. The second time series data is time series data of an air-fuel ratio detection variable in a second predetermined period.

Abstract: At the time of stopping operation of the vehicle, the pressures inside of the fuel tank (5) and inside of the canister (6) detected at every constant time are stored in the storage device. A learned neural network using the pressures inside the fuel tank (5) and inside the canister (6) for each fixed time stored in the storage device and the atmospheric pressure as input parameters of the neural network and using a case where perforation occurs in the system causing fuel vapor to leak as a truth label is stored. At the time of stopping operation of the vehicle, a perforation abnormality causing fuel vapor to leak is detected from these input parameters by using the learned neural network.

Abstract: A method is described for diagnosing errors in an internal combustion engine in which fuel is injected from a high-pressure accumulator into associated combustion chambers with the aid of multiple fuel injectors, a first value (Rstat,2) which is representative of a static flow rate of fuel through one of the fuel injectors being ascertained, a second value (?n) which is representative of a running smoothness of the internal combustion engine being ascertained, if at least one of the two values (Rstat,2, ?n) deviates from the particular associated reference value (R?stat, ?n0), an error (F) being deduced, and the error (F) being assigned to the fuel injector and/or at least one further component and/or at least one operating phase of the internal combustion engine on the basis of deviations of the two representative values (Rstat,2, ?n) from the particular associated reference value (R?stat, ?n0).

Abstract: A controller includes a P/L learning unit that performs P/L learning, a purge learning unit that performs purge learning, an air-fuel ratio learning unit that performs air-fuel ratio learning, and a storage unit that stores learning result. When the learning result of each learning process is not stored in the storage unit at the time of engine start, the P/L learning unit learns an injection characteristic of an in-cylinder injection valve through the P/L learning process whenever the in-cylinder injection valve performs the P/L injection and interrupts the P/L learning process before the P/L learning process is completed. The purge learning unit performs the purge learning process, and the air-fuel ratio learning unit starts the air-fuel ratio learning process provided that the P/L learning process is interrupted. The P/L learning unit then resumes the P/L learning process provided that the purge learning process is completed.

Abstract: A method of controlling a fuel injection quantity using a lambda sensor may include performing a lambda deviation learning mode by controlling a lambda deviation, due to a difference between a lambda model value and a lambda sensor measurement value, by a controller during engine combustion in which an engine RPM and a fuel injection quantity are detected, wherein, in the lambda deviation learning mode, a learning map is learned and is then updated by setting a fuel correction quantity depending on the lambda deviation as a learning value, and a fuel injection quantity is determined, in consideration of the fuel correction quantity depending on an RPM and a fuel quantity based on the updated learning map, and is output as an output value, so that the output value is applied to feedback control for a next fuel injection quantity.

Abstract: A failure prediction system having small boats operable by operators, each mounted with an outboard motor equipped with an engine and an Electronic Control Unit and a computer located in a land office connected to the ECU. The ECU acquires boat ID assigned to one small boat on which one operator boards and his personal ID, accesses the computer to acquire past manipulation data of the acquired personal ID for all boats, acquires manipulation data of the one operator during current run, merge the data with past data to generate merged data. Then, it select a parameter in the generated data and set a normal value range by the parameter, assesses whether parameter in the data during current run is within the range, and determines the outboard motor mounted on the one boat is in failure when the parameter is out of the range.

Abstract: Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to one or more of intake manifold air temperature (MAT), intake air flow rate, or a sensed or estimated intake oxygen fraction by changing an exhaust gas recirculation (EGR) amount to maintain particulate matter (PM) and NOx within a range, and then further adjusting the EGR amount based on NOx sensor feedback.

Abstract: This fuel property estimation device is used in an internal combustion engine that uses a mixed fuel of three kinds of fuel and includes a first sensor that outputs a signal responsive to a physical property of the fuel in a fuel route and a second sensor outputs a signal responsive to an oxygen concentration of exhaust gas. This device measures a physical property value of the mixed fuel based on a first sensor signal, and calculates an air-fuel ratio value at stoichiometric combustion state using feedback of a second sensor signal. This device estimates a composition ratio of the mixed fuel based on the measured physical property value and the calculated air-fuel ratio value by referring to a relationship between the composition ratio of the mixed fuel and the physical property value and a relationship between the composition ratio of the mixed fuel and a theoretical air-fuel ratio value.

Abstract: A fuel supply system for use with an internal combustion engine has a check valve and a purge valve disposed in a purge passage that extends from a canister to connect with an intake passage of the internal combustion engine. A controller regulates the purge valve open with a first opening degree or a first duty ratio during a purge operation. The controller may also regulate the purge valve to open with a second opening degree larger than the first opening degree or a second duty ratio larger than the first duty ratio a predetermined time after initiating the purge operation.

Abstract: A control device for an internal combustion engine includes an electronic control unit configured to switch a control algorithms for a calculation of a command value of the actuator between a first control algorithm and a second control algorithm. The electronic control unit is configured to calculate a value obtained by adding a value of a term of the second control algorithm changing in accordance with the deviation calculated in a present control cycle to the command value calculated in a previous control cycle in accordance with the first control algorithm as a value of the command value calculated in the present control cycle in a first control cycle after switching from the first control algorithm to the second control algorithm. The value of the term changing in accordance with the deviation includes an update amount of an I term of the I control calculated in the present control cycle.

Abstract: The air-fuel ratio feedback control is performed by using a first correction value which is determined depending on a difference between a detected air-fuel ratio (A/F) of an air-fuel mixture and a target A/F and a second correction value which is determined depending on the property of the fuel. Further, fuel property learning control is carried out to correct the first correction value and the second correction value so that an absolute value of the first correction value is not more than a threshold value, when the absolute value of the first correction value is larger than the threshold value after performing the charging with fuel.

Abstract: A PCM (60) as an engine control device comprises a torque controlling unit (65) configured to control an engine torque based on an accelerator actuated amount. The torque controlling unit (65) is configured, after an accelerator actuated amount is started to increase, and when a rolling movement is being produced in a power train (PT) which includes at least an engine fixed to a vehicle body by an engine mount, to control for limiting increase in the engine torque so as to make an actual increase rate of the engine torque smaller than a nominal increase rate of the engine torque according to an increase in the accelerator actuated amount, in order to suppress the rolling movement.

Abstract: Provided are an apparatus and a method for compensating for a fuel injection quantity in an engine of a vehicle. The apparatus for compensating for a fuel injection quantity may include: an information collector collecting status information of the vehicle; an oxygen sensor outputting a voltage corresponding to a concentration of oxygen in exhaust gases; a high pass filter (HPF) filtering the output voltage of the oxygen sensor; and a controller generating a reference value on the basis of the status information of the vehicle. In particular, the controller calculates an offset using the reference value and a signal obtained by high-pass filtering the output voltage, and compensates for a fuel injection quantity in each individual cylinder of the engine of the vehicle on the basis of the offset.

Abstract: The present disclosure provides a system for adjusting a fuel injector drive signal during a fuel injection event wherein the system comprises an engine having a fuel injector, a fuel control module configured to generate control signals corresponding to a desired fueling profile of a fuel injection event, and a fueling profile interface module that outputs drive profile signals to the fuel injector in response to the control signals to cause the fuel injector to deliver an actual fueling profile, wherein the fueling profile interface module changes the drive profile signals during the fuel injection event in response to a parameter signal indicating a characteristic of the actual fueling profile.

Abstract: A PCM (60) as an engine control device comprises a torque controlling unit (65) configured to control an engine torque based on an accelerator actuated amount. The torque controlling unit (65) is configured, after the accelerator actuated amount is started to increase, and when a power train (PT) which includes at least an engine (E) fixed to a vehicle body by an engine mount (Mt) is started to conduct the rolling movement, to control to limit increase in the engine torque so as to make an actual increase rate of the engine torque smaller than a nominal increase rate of the engine torque according to an increase in the accelerator actuated amount, in order to control an initial speed of the rolling movement.

Abstract: In one example, fleet devices are monitored. The fleet devices include engines. A controller, such as an engine controller or centralized controller, receives sensor data indicative of a load on the engine from one or more of the fleet devices. The controller analyzes the load from the sensor data to identify a management function. The controller generates a message including the management function.

Abstract: A method is provided for controlling an internal combustion engine on a cycle-by-cycle basis. The method includes: maintaining training data used to identify a mapping function for the engine; populating a buffer with adaptive data for a given cylinder, where the adaptive data are measures of the inputs and the output of the mapping function that were captured during a number of recent operating cycles of the given cylinder; combining training data for the mapping function with the adaptive data; identifying the mapping function from the combined data set using a weighted least squares method; predicting a combustion feature of the given cylinder in the next cycle using the mapping function and measures of the inputs during the present cycle; and controlling the engine based in part on the predicted combustion feature of the given cylinder in the next cycle using one or more actuators.

Abstract: A fuel vapor processing apparatus may include a canister capable of adsorbing fuel vapor produced in a fuel tank, a closing valve provided in a vapor passage connecting the canister and the fuel tank, a purge passage connecting the canister and an intake passage of an engine, and a control device. The closing valve may include a movable valve member movable along a linear path and an actuator coupled to the movable valve member. The control device may be coupled to the actuator and may be configured to control the actuator such that the position of the movable valve member along the linear path changes according to a deviation of an actual tank internal pressure of the fuel tank from a target tank internal pressure.

Abstract: Fuel injector wear compensation methodologies for use with internal combustion engines that alter the injection schedule over the life of the fuel injector(s) by using methods that conduct a primary injection of fuel in the engine (primary fuel event), per an injection schedule within an engine cycle; compare a measured engine parameter(s) to a reference value(s); and then alter the injection schedule applied to the engine, based on the comparing. Another method comprises: during injection events, inject a first fuel in a combustion chamber of the engine; measure an engine parameter(s) of the engine during operation; compare the engine parameter(s) to a reference value(s); add a post injection event of a second fuel during the injection events, based on the comparison. The methods can be applied with single or dual fuels.

Abstract: The exhaust purification system comprises a control apparatus performing main feedback control controlling the amount of fed fuel so that the output air-fuel ratio of the upstream side sensor becomes a target value, sub feedback control setting the target air-fuel based on the output air-fuel ratio of the downstream side sensor, main learning control controlling the amount of fed fuel based on a main learning value, and sub learning control controlling the amount of fed fuel based on a sub learning value. The control apparatus performs sub learning promotion control so that the sub learning value easily changes to a suitable value when a sub learning promotion condition, which is satisfied when the absolute values of the main learning value and the sub learning value are respectively predetermined reference absolute values or more and these learning values are opposite in sign, is satisfied.

Abstract: Methods and systems are provided for detecting cylinder air-fuel imbalance. In one example, a method may include adjusting engine operation based on an indication of cylinder air-fuel imbalance. The imbalance may be detected based on output from a second exhaust gas sensor and a plurality of individual cylinder weighting factors, the second sensor located in an exhaust system downstream of a first sensor located in the exhaust system.

Abstract: A method for an engine may comprise, responsive to a first condition comprising a reference voltage of a first exhaust oxygen sensor operating in variable voltage mode increasing above a threshold voltage, determining a change in an output of the first exhaust oxygen sensor corresponding to the increase in the reference voltage, correcting the output of the first oxygen sensor based on the output change, and adjusting engine operation based on the corrected output. In this way, the accuracy of air-fuel estimates based on the exhaust gas sensor can be preserved, and closed loop fuel control of the engine can be maintained even when the exhaust oxygen sensor is operating VVS mode, thereby reducing engine emissions, increasing fuel economy, and increasing vehicle drivability.

Abstract: An evaporated fuel processing apparatus includes: a fuel tank that stores fuel supplied to an engine; a purge pipe that communicates an upper space in the fuel tank with an inlet system of the engine; an electromagnetic valve that is mounted on the purge pipe and that opens and closes the purge pipe; an air-fuel ratio detecting module for detecting an air-fuel ratio of an air-fuel mixture burned in the engine in accordance with an oxygen concentration in exhaust gas emitted from the engine; and a controlling module for controlling open and close of the electromagnetic valve based on an operating state of the engine. The controller controls at least one of a valve-open cycle, a valve-open period, and a valve-open amount of the electromagnetic valve based on a variation value of the air-fuel ratio detected by the air-fuel ratio detecting module when opening the electromagnetic valve.

Abstract: A method comprising adjusting a fuel injection amount based on a fractional oxidation state of a catalyst, the fractional oxidation state based on reaction rates of grouped oxidant and reductant exhaust gas species throughout a catalyst and a low-dimensional physics-based model derived from a detailed two-dimensional model to obtain a one-dimensional model averaged over time and space that accounts for diffusion limitations in the washcoat and accurately predicts emissions during cold start.

Abstract: An air feed ratio controlling apparatus can include a predictor for predicting an air fuel ratio on the downstream side of a catalyst calculates a predicted air fuel ratio at least based on an actual air fuel ratio from an oxygen sensor and a history of a first correction coefficient. The air fuel ratio controlling apparatus can also include an adaptive model corrector which determines the deviation between the actual air fuel ratio and the predicted air fuel ratio as a prediction error ERPRE, and superposes a second correction coefficient on the first correction coefficient so that the prediction error may be reduced to zero.

Abstract: An ECU acquires a fluid temperature, a coolant temperature and a soak time, and determines whether vapors have been produced in a fuel supply device on the basis of a vapor production prediction map. When the ECU determines that vapors have been produced in the fuel supply device, the ECU reduces a feedback gain. Subsequently, the ECU predicts a vapor production time, and, when the ECU determines that a vapor production end time has been reached, executes normal feedback control.

Abstract: Systems and methods for adjusting an engine air flow transfer function and engine actuators based on the engine air flow transfer function are presented. The system and method may be applied to hybrid powertrains having a capability to estimate engine torque based on operating characteristics of a motor during vehicle operation.

Abstract: The present invention provides apparatus featuring a signal processor or processing module that may be configured at least to: process signaling containing information about an equilibrium point of pump differential pressure and system pressure formulated in a hydronic domain by utilizing pump and system characteristic curve equations so as to yield system pressure and flow rate at any particular load and time in a pump hydronic system, including using a multi-dimensional sensorless conversion technique; and determine equivalent hydronic system characteristics associated with the pump differential pressure and flow rate to their corresponding motor power and speed reconstructed and remapped by using a discrete numerical approach, based at least partly on the signaling received. The signal processor or processing module may provide corresponding signaling containing information about the system pumping flow rate and pressure determined.

Abstract: A fuel injection apparatus includes an injector that injects fuel into a combustion chamber or an intake port of an internal combustion engine; an injection amount controller that controls a fuel injection amount of the injector and corrects the fuel injection amount to increase when the internal combustion engine is in a given cold state; an air-fuel ratio detector that detects an air-fuel ratio of the internal combustion engine; and an air-fuel ratio rich fault determiner that determines an air-fuel ratio rich fault when the air-fuel ratio exists on a rich side than a predetermined determination value. The air-fuel ratio rich fault determiner shifts the predetermined determination value toward the rich side in accordance with the increasing correction of the fuel injection amount so as to correct the predetermined determination value.

Abstract: An apparatus includes an air-fuel ratio sensor installed in an exhaust passage common to a plurality of cylinders in a multicylinder internal combustion engine, and a control apparatus configured to detect an inter-cylinder air-fuel ratio variation abnormality based on a parameter correlated with a degree of variation in output from the air-fuel ratio sensor. The control apparatus is configured to calculate a division crank angle that bisects an area of a region present in at least one of a rich and a lean sides with respect to a mean value of an output waveform from the air-fuel ratio sensor during one cycle of the internal combustion engine or such a predetermined constant value as corresponds to a center of fluctuation in the output waveform and to identify an abnormal cylinder with a deviation of the air-fuel ratio based on the division crank angle.

Abstract: An ECU executes a cylinder-by-cylinder air-fuel-ratio control in which an air-fuel-ratio of each cylinder is estimated based on a detection value of an air-fuel-ratio sensor to adjust the air-fuel-ratio of each cylinder. Further, the ECU computes a learning value of a correction quantity for each cylinder, which is obtained by executing the cylinder-by-cylinder air-fuel-ratio control. Then, the ECU determines whether the estimated air-fuel-ratio has converged according to whether the estimated air-fuel-ratio of each cylinder has been closer to a target value than a specified value for not less than a specified time period. A computation of the learning value is prohibited until the estimated air-fuel-ratio has converged. Therefore, it can be avoided to compute the learning value based on the fuel correction quantity that is obtained when the estimated air-fuel-ratio has not converged yet.

Abstract: Various embodiments include systems adapted to monitor catalyst deterioration. Some embodiments include a catalyst deterioration detection system including a pre-catalytic converter gas sensor, a post-catalytic converter gas sensor, at least one computing device in communication with the pre-catalytic converter and post-catalytic converter gas sensors, the at least one computing device configured to monitor catalyst deterioration by performing actions including estimating a catalyst gas storage level by comparing a difference between a pre-catalytic converter gas level from the pre-catalytic converter gas sensor and a post-catalytic converter gas level from the post-catalytic converter gas sensor, comparing the estimated catalyst gas storage level to a baseline catalyst gas storage level and determining that the catalyst is deteriorated in response to the baseline catalyst gas storage level exceeding the estimated gas storage level by a threshold difference.