Abstract: A control system includes a temperature determination module and a heater control module. The temperature determination module determines a temperature of an oxygen sensor in an exhaust system of an engine. The heater control module applies a heat cycle to combust deposits on the oxygen sensor by activating a heating element of the oxygen sensor to increase the temperature of the oxygen sensor to greater than 800 degrees Celsius.

Abstract: An exhaust gas pressure P, exhaust gas temperatures TU and TD on upstream and downstream of a DPF, a rotation speed Ne, a load Q, and an intake flow rate F as various operating conditions are read, and an amount of PM generated for short time ?t is obtained to be added to a PM deposited amount m, and thus, to obtain an initial deposited amount. Exhaust gas properties and a space velocity SV are obtained based on various operating conditions, and the PM deposited amount m after a lapse of the short time ?t is estimated from a PM deposited amount estimation equation “m=m·exp(?B·?t)” having been derived considering the exhaust gas properties and the space velocity SV. When the PM deposited amount m is equal to or more than a predetermined value, a forced regeneration processing in the DPF is executed, and thereafter, the PM deposited amount m is reset to 0.

Abstract: An exhaust line of a motor vehicle includes a heat exchanger having a first side for circulating the exhaust gases and a second side for circulating a heat exchange fluid, and a closed recovery cycle for one portion of the heat energy of the exhaust gases, in which said heat exchange fluid circulates, wherein the second side of the heat exchanger is inserted inside the closed cycle. The heat exchanger includes an intermediate wall interposed between the first and second sides of the heat exchanger. The intermediate wall comprises at least one closed cavity including a phase change material. The intermediate wall has a first exchange surface in thermal contact with the exhaust gases and a second exchange surface in thermal contact with the heat exchange fluid.

Abstract: A vehicle includes an engine, an exhaust system having a selective catalytic reduction (SCR) device, a NOx sensor, and first and second controllers. The first controller compares estimated NOx levels from an SCR model to actual levels from the sensor, and updates the SCR model when the values differ from each other. The second controller evaluates an updating frequency of the SCR model, and executes a control action when the frequency is excessive. A control system includes the sensor and two controllers noted above. A method of diagnosing the exhaust system includes measuring NOx gasses downstream of the SCR device, updating the SCR model when the deviation is present between estimated and measured NOx levels, comparing estimated ammonia (NH3) storage levels from the SCR model to modeled or estimated upper and lower NH3 storage level boundaries to determine excessive updating, and setting a diagnostic code when excessive updating is present.

Abstract: The invention relates to a device for supplying a reducing agent into an exhaust system of an internal combustion engine. The device includes a delivery pump for delivering the reducing agent from a storage tank into an exhaust tube of the exhaust system. A metering device is provided between the delivery pump and the exhaust tube, which metering device supplies reducing agent, which is delivered continuously by the delivery pump, in an intermittent fashion into the exhaust tube.

Abstract: When performing temperature elevation control at a first exhaust purification device, a second exhaust purification device is prevented from being raised in temperature to a set temperature or more.

Abstract: The present invention relates to a method and system for homogenizing exhaust from an engine. In one embodiment, the present invention includes an automobile. The automobile can include a fuel delivery unit, an engine, an exhaust system, and a control unit. The exhaust system can include a swirl inducement unit, multiple sensors, and multiple catalytic converters. The swirl inducement unit can homogenize an exhaust from the engine. The swirl inducement unit can include a plurality of vanes and/or a plurality of protrusions. The protrusions can be a plurality of bumps and/or a plurality of semi-circular rings. The plurality of vanes can be rotatable with the rotation of the vanes being controlled by the control unit. The rotation of the vanes can be based on an operating condition of the engine.

Abstract: A variety of embodiments of exhaust systems for engines including small off-road engines, and related methods of operation, are disclosed. In at least some embodiments, the exhaust system includes a first conduit that receives exhaust emissions from a first engine cylinder, and a second conduit that communicates air to a first port on the first conduit. The air mixes with the exhaust emissions within the first conduit so as to produce a chemical reaction, and a level of at least one undesirable component of the exhaust emissions is reduced. Further, the exhaust system does not include any catalytic converter. In some embodiments, the exhaust system further comprises a crankcase ventilation system.

Abstract: A regeneration system includes a particulate matter (PM) filter loading module that determines a current soot loading level of a PM filter. A PM filter temperature module determines a temperature of the PM filter. An exhaust flow rate module determines an exhaust flow rate of the PM filter. A control module deactivates an air pump of an air pump circuit and operates an engine within a predetermined range of stoichiometry based on the current soot loading, the temperature and the exhaust flow rate.

Abstract: A component of an exhaust system for a combustion engine, particularly of a motor vehicle, has a hollow jacket at least partially surrounding the component. An intermediate space is surrounded by the walls of the hollow jacket and is closable in a pressure-tight manner. The intermediate space is fluidically connected to a vacuum generating device via a vacuum connection line and via a vacuum connection point of the component. With the vacuum generating device, a vacuum can be generated in the intermediate space. Through arrangement of a filler material, such as a support structure and/or of a fiber material and/or of a foam, in the intermediate space the stability of the hollow jacket can be improved.

Abstract: In one exemplary embodiment, an exhaust dilution and dispersion device for a vehicle can include a generally elongate tailpipe comprising an inlet section capable of being in exhaust receiving communication with an exhaust system of a vehicle. The tailpipe further comprises an outlet section in exhaust receiving communication with the inlet section. The outlet section can also comprise a downwardly directed exhaust deflection portion and an exhaust outlet in exhaust dispersing communication with the surroundings external to the device. The exhaust outlet can comprise a generally elongate exhaust dispersion opening extending in a lengthwise direction along the tailpipe. At least a portion of the exhaust outlet can be coextensive with the downwardly directed exhaust deflecting portion and a major portion of the exhaust dispersed from the outlet can have a transverse component.

Abstract: The invention intends to provide a technology which makes it possible to diagnose with higher accuracy whether or not abnormality occurs in a filter regeneration system causing excessive execution frequency of a regeneration process. The filter regeneration system initiates execution of the regeneration process, incase an estimated particulate matter (PM) accumulation amount at the filter reaches a pre-determined regeneration requiring accumulation amount; or in case the pressure upstream of the filter or the differential pressure across the filter reaches a pre-determined regeneration requiring value, the value being larger than the pressure or the differential pressure corresponding to the regeneration requiring accumulation amount. Then, the diagnosis is carried out based on a ratio of an estimated PM accumulation amount at the initiation of the execution of the regeneration process to the regeneration requiring accumulation amount.

Abstract: The invention concerns a procedure to determine the sulfur removal of a NOx storage catalytic converter in an exhaust gas aftertreatment system of an internal combustion engine, whereby conditions, in which a surplus of the reducing agent is generated in the internal combustion engine, are adjusted in the internal combustion engine for the sulfur removal, whereby a SOx removal amount is determined in a SOx removal calculation using a model from the reducing agent flow and from additional operating parameters of the internal combustion engine. In so doing, dynamic effects during the desulferization of the NOx storage catalytic converter can be better taken into account for the SOx removal calculation; and in so doing, the subsequent effect of the NOx storage catalytic converter on the reduction of the nitrogen oxides in the exhaust gas can be more accurately predicted, which makes the process management more streamlined and consequently more fuel efficient.

Abstract: A control system may include an adsorber bypass evaluation module, an adsorber bypass control module and an engine operation control module. The adsorber bypass evaluation module may evaluate a bypass closing criterion of a hydrocarbon adsorber bypass passage in an engine exhaust gas treatment device after an engine key-on condition. The adsorber bypass control module may be in communication with the adsorber bypass evaluation module and may close the hydrocarbon adsorber bypass passage after the key-on condition when the bypass closing criterion meets a predetermined condition. The engine operation control module may be in communication with the adsorber bypass control module and may start the engine after the closing.

Abstract: Intake air heating and exhaust cooling is provided by a double wall exhaust system serving as an exhaust-to-air heat exchanger, sourcing hot air to the intake manifold for intake stroke pumping benefit and cooling the exhaust system during high load operation by routing excess boost air through an interstitial space of the double wall.

Abstract: A diesel combustion engine comprises multiple particulate filters and corresponding exhaust piping and valving in the exhaust manifold and/or exhaust line, configured to enable regeneration to occur in one of the DPF filters through heating the exhaust from a single cylinder of the engine, while the exhaust from the remaining cylinders is temporarily routed through the other DPF filter during the regeneration event. Flow redirection devices are placed within the DPF filters to direct flow of exhaust gas through the DPF filters during regeneration in a manner to facilitate complete regeneration, including in outer volumes along the interior walls of the DPF filters.

Abstract: By using catalytic partial oxidation or autothermal reforming process, a catalytic oxidizer installed in the engine's Exhaust Gas Recycle (EGR) line can be used to produce from fossil fuels or bio-fuels a reformate gas containing H2 and CO for an IC engine or a gas turbine. Thus, a system consisting of an EGR Oxidizer and an IC engine/gas turbine can be used by itself as a driving device, or can be combined with an electric generator and a battery bank to produce, store and transmit electricity to be used in stationary or mobile power generation, transportation and utility etc. The Oxidizer can also be used to provide reducing gases to regenerate the NOx or diesel particulate traps, so that the traps can continuously be used for reducing emissions from IC engine, diesel truck, gas turbine, power plant etc.

Abstract: An regeneration system for use in a power system is disclosed. The regeneration system may include a source of intake air, an engine brake configured to reduce the speed of an engine by compression and release of the intake air, and a valve configured to divert a portion of the intake air to an auxiliary device. The regeneration system may further include a controller in communication with the engine brake and the valve. The controller may be configured to move the valve to reduce the portion of intake air diverted to the auxiliary device when the engine brake is active.

Abstract: A diesel engine and method for operating a diesel engine with exhaust after-treatment device regeneration capability are disclosed. The diesel engine may employ an exhaust after-treatment device such as a diesel particular filter to remove soot from the combustion gases exhausted by the engine. In order to regenerate the exhaust after-treatment device, the temperature of the exhaust gases is raised sufficiently to do so. The temperature of the exhaust gases is raised to such a level by employing multiple compression and expansion strokes of the piston in certain engine cycles, with a combustion event associated with each pair of compression and expansion strokes. The engine may operate in a four stroke, one combustion cycle during conventional power operation, and switch to an enhanced combustion cycle during regeneration. The enhanced combustion cycle may include eight strokes such as one intake stroke, three compression strokes, three expansion strokes, and one exhaust stroke, with three combustion events.

Abstract: The diagnosis of the heating of a catalytic converter situated in an exhaust system of an internal combustion engine is described. The system includes monitoring the actual ignition angle intervention. A current ignition angle is acquired over a specified time and converted into a torque model used for catalytic converter heating. Using the torque model, a degree of fulfillment of executed catalytic converter heating measures is obtained and an error signal is generated by comparing the obtained degree of fulfillment to a limiting value.

Abstract: An exhaust gas system is provided for an internal combustion engine that includes, but is not limited to an exhaust gas line and a turbine of an exhaust gas turbocharger. The turbine being situated in the exhaust gas line, the exhaust gas line having a bypass duct leading past the turbine, whose inlet is situated upstream and whose outlet is situated downstream from the turbine in the exhaust gas line, a catalytic converter being situated in the bypass duct.

Abstract: An exhaust-gas sampler is adapted to couple into an exhaust conduit and to sample a constituent of an engine exhaust flowing therein. The sampler comprises an envelope having upstream and downstream surfaces joined by a curved side surface. The upstream and downstream surfaces are each tangent to a plane substantially normal to a central axis of the exhaust conduit. A series of inlets are formed in the upstream surface, and an outlet is formed in the curved side surface. A sensor responsive to a level of the constituent in the exhaust is coupled in the envelope, at the peripheral region of the conduit.

Abstract: An engine having one of a plurality of exhaust valves in each cylinder that may be deactivated is disclosed. In one example, one exhaust valve of each cylinder is deactivated in response to engine speed. The engine may have improved engine torque at low engine speeds and reduced time to torque (e.g., turbo lag).

Abstract: Intake air heating and exhaust cooling is provided by a double wall exhaust system serving as an exhaust-to-air heat exchanger, sourcing hot air to the intake manifold for intake stroke pumping benefit and cooling the exhaust system during high load operation by routing excess boost air through an interstitial space of the double wall.

Abstract: A method for inducing the regeneration of a particulate filter associated with an exhaust gas emitting tinning engine while being operated in a vehicle in variable driving conditions. The method includes turning on, for a time period, a heating device substantially in punctual contact with the filter at its gas entrance. The turning on of the heating device is subject to the following conditions: i) an average pressure of the exhaust gas at the entrance of the filter is greater than a predetermined value; and ii) an instantaneous pressure of the exhaust gas at the entrance of the filter is at a high improbable value. The time period for such heating device to stay turned on is sufficiently long to reach the particulate ignition temperature and for such instantaneous pressure to get from such high improbable value to a significantly lower value. The avenge pressure is obtained by averaging a plurality of pressure data sensed at the entrance of the filter.

Abstract: A system is provided for monitoring and testing engine emissions during normal operations. The system monitors and logs engine data to determine when the engine is operating at a steady-state within a defined test mode. The system may measure and log multiple sets of emissions data while the engine is operating in the defined test mode. The multiple sets of emissions data may be aggregated for qualifying the engine and may provide trend information about the engine. The test mode definition may be revised based on the logged engine data. The system may be used to selectively monitor one or more of a set of multiple engines.

Abstract: A system and method are provided for cleaning combustion soot from an exhaust gas aftertreatment sensor. The system and method determine whether to conduct a sensor desoot event, and if it is determined that a sensor desoot event is to be conducted, the exhaust gas temperature is increased such that the temperature of the sensor correspondingly increases to or above a desoot temperature, the exhaust gas temperature is then controlled to maintain the temperature of the sensor at or above the desoot temperature for a predefined time period, and the exhaust gas temperature is then decreased after the temperature of the sensor has been at or above the desoot temperature for the predefined time period.

Abstract: A method is provided for reducing emissions behind a catalytic converter in an exhaust gas stream of the engine. The method includes, but is not limited to controlling a power supply to a glowplug of a compression-ignition engine. The glowplug is activated if a set of at least two input values remains in a first characteristic region of an input parameter space for at least a predetermined activation time. The first characteristic region consists of one ore more contiguous regions of the input parameter space.

Abstract: A method for operating an international combustion engine, the engine also includes a first cylinder, a second cylinder, an exhaust system, and a fuel cell in the exhaust system. The method comprises operating the first cylinder lean to provide air to the fuel cell during at least one condition; and operating the second cylinder rich or stoichiometric to provide torque output and fuel to the fuel cell.

Abstract: A warm-up system for warming up an exhaust purification catalyst arranged in an exhaust passage of an engine equipped with a turbocharger. The warm-up system includes an electric motor coupled to a turbine of the turbocharger, and control device that operates the electric motor to apply counter torque to the turbine when the exhaust purification catalyst needs to be warmed up.

Abstract: An exhaust gas cooler assembly with an internally located bypass tube, spaced apart from and disposed within a core passage, with an exhaust gas inlet manifold directing exhaust gas to a plurality of cooling passages, or to the bypass tube by means of control valves. Further provided is a detachable valve cartridge with an actuator, with all moving components being included within the valve cartridge and actuator.

Abstract: A system is provided for inerting a volume in a vehicle has at least one exhaust gas extraction point on at least one internal combustion engine of the vehicle, and exhaust gas line for routing exhaust gas from the exhaust gas extraction point to the volume, and at least one exhaust gas inlet on the volume for introducing exhaust gas to generate a low-activity environment in the volume. Precisely in vehicles with internal combustion engines, using exhaust gas for inerting a volume makes it possible to suggest an especially simple, cost-effective and robust solution to guard against the formation of an ignitable mixture in the volume or the like.

Abstract: An exhaust purifying system for an engine includes: a soot filter being provided to a PM filter device to collect PM contained in exhaust gas; a regeneration execution judging unit being provided to a controller to decide whether or not the soot filter should be regenerated; an air cooled aftercooler that cools intake air being supercharged by a turbocharger; a cooling fan that supplies cooling air to the aftercooler and a forced-regeneration fan rotation speed controlling unit being provided to the controller to lower the rotation speed of the cooling fan when the regeneration execution judging unit decides that the soot filter needs to be regenerated.

Abstract: The present application relates to mitigating NOx emissions, and more particularly, to vehicles including a selective catalytic reduction (SCR) system in the exhaust of a diesel or gasoline engine. In one example a method includes temporarily increasing a liquid reductant dosing value injected by an injector from a first dosing value to a second dosing value, the temporary increase in response to a change from injecting liquid reductant onto a first impact location on a disperser device to injecting onto a second impact location on the disperser device.

Abstract: An exhaust diagnostic system includes a selective catalyst reduction (SCR) efficiency testing module that determines an efficiency of a SCR catalyst. An exhaust gas temperature management module selectively adjusts a temperature of the SCR catalyst to a predetermined temperature range using intrusive exhaust gas temperature management. A test enabling module initiates an SCR efficiency test using the SCR efficiency module after failing a prior SCR efficiency test and while the temperature of the SCR catalyst is within the predetermined temperature range.

Abstract: According to one embodiment, an apparatus for controlling the heating of diesel exhaust fluid (DEF) in a DEF delivery system includes a temperature comparison module that compares a difference between a sensed ambient air temperature and a sensed DEF tank temperature with a predetermined temperature difference threshold. Additionally, the apparatus includes a DEF heating status module that is configured to generate a DEF heating command according to (i) the sensed ambient air temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is less than the predetermined temperature threshold; and (ii) the sensed DEF tank temperature if the difference between the sensed ambient air temperature and sensed DEF tank temperature is more than the predetermined temperature threshold. The apparatus also includes a DEF heating control module that is configured to control the heating of the DEF according to the DEF heating command.

Abstract: The present invention relates to the use of a lubricant in a diesel engine equipped with a regenerable diesel particulate trap, wherein the lubricant comprises a base oil component having a paraffin content of greater than 80 wt % paraffins, a saturates content of greater than 98 wt %, and comprising a series of iso-paraffins having n, n+1, n+2, n+3 and n+4 carbon atoms, wherein n is between 15 and 40, and to a process for operating a diesel engine equipped with a diesel particulate trap, comprising lubricating the diesel engine with the lubricant.

Abstract: One embodiment is a method including operating an SCR system at a plurality of commanded ammonia to NOx input ratios, providing a plurality of data indicating NOx output from the SCR system for the plurality of commanded ammonia to NOx input ratios, and evaluating the plurality of data to diagnose the SCR system. Additional embodiment are methods, systems, and apparatuses including SCR diagnostics. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Abstract: In a method for an emission-optimized transition between a spark-ignition mode of an internal combustion engine and a self-ignition mode of the internal combustion engine, the internal combustion engine is operated in the preparation phase and chronologically before the transition of modes in a spark-ignition mode in at least one cylinder cycle with a rich mixture (?<1) and, subsequently, in the same cylinder cycle with a lean mixture (?<1). After that, the internal combustion engine is operated in the self-ignition mode. In a method for an emission-optimized transition between a self-ignition mode of an internal combustion engine and a spark-ignition mode of the internal combustion engine, in a transition phase of the operation modes and during a last cycle of the self-ignition mode and/or a first cycle of the spark-ignition mode, fuel is post-injected into at least one combustion chamber of the internal combustion engine.

Abstract: An exhaust emission control system for an internal combustion engine with a filter provided in the exhaust system of the engine, for collecting particulates from exhaust gases. An ECU carries out the post injection for additionally injecting fuel into a combustion chamber of the engine after a combustion stroke of the engine to thereby perform a regeneration operation for regenerating the filter. A vehicle speed sensor detects a travel distance of a vehicle on which the engine is installed, and the ECU calculates a post injection allowable amount such that the post injection allowable amount increases in accordance with increase in the detected travel distance. During execution of the post injection, the amount of fuel injected through the post injection is subtracted from the post injection allowable amount, and when the post injection allowable amount becomes equal to or smaller than a predetermined first threshold value, the post injection is inhibited.

Abstract: A method and a control system are provided for estimating oxygen concentration downstream a diesel oxidation catalyst within a diesel engine system. The method includes, but is not limited to at least an intake manifold, a combustion chamber, an exhaust manifold, and the diesel oxidation catalyst located in the exhaust line upstream a diesel particulate filter, the method comprising: determining unburned fuel mass flow ejected from the combustion chamber, determining air mass fraction in the exhaust manifold, estimating air mass fraction downstream the diesel oxidation catalyst as a function of said unburned fuel mass flow and said air mass fraction in the exhaust manifold, estimating oxygen concentration downstream the diesel oxidation catalyst as a function of the estimated air mass fraction downstream the diesel oxidation catalyst.

Abstract: In a method for operating a lambda sensor disposed in an exhaust gas system of an internal combustion engine,—the heating element is subjected to a predefined heating power substantially with the start of the engine;—during the heating process, the sensor signal is detected and compared to a threshold value specified for a lean and/or rich fuel/air mixture ratio, wherein the threshold value correlates with a sensor temperature, which is below the water ingestion critical temperature, and to a valid lambda signal,—when one of the specified threshold values is reached for the first time, a measured variable correlating with the sensor temperature is determined and the lambda signal is set as valid and forwarded, and—the determined measured variable correlating with the sensor temperature is transferred to a closed heating element control loop as a target value that corresponds to a target temperature.

Abstract: A method for determining the charge state of a particle filter installed in the exhaust gas line of an internal combustion engine comprises the following steps: determining the exhaust gas volumetric flow in the flow direction of the exhaust gas downstream of the particle filter (2), detecting the pressure present in the exhaust gas line (1) in the direction of flow of the exhaust gas prior to the particle filter (2), comparing the exhaust gas volumetric flow determined hinter the particle filter (2) with the detected pressure present upstream of the particle filter (2) and evaluating the results of the comparison with consideration to the exhaust gas back pressure of the uncharged particle filter (2) and the exhaust gas back pressure caused by the particle filter charge, said pressure being higher than the uncharged filter. Further described is a corresponding device for reducing the particle emissions of an internal combustion engine.

Abstract: A method for improving engine control during a regeneration of an exhaust gas after treatment device is described. According to one aspect of the description, engine air amount and engine fuel amount may be adjusted based on data from a previously executed regeneration of an exhaust gas after treatment device.

Abstract: An exhaust gas control system and an exhaust gas control method are provided. The exhaust gas control system includes an exhaust gas throttle valve in an exhaust gas duct and an actuation device of the exhaust gas throttle valve having an actuating rod. An exhaust gas pressure control device controls the exhaust gas pressure occurring upstream of the exhaust gas throttle valve in the exhaust gas duct. The actuating rod also includes a control actuator that interacts with a pressure compensation volume. The pressure compensation volume is pneumatically connected to a throttle opening upstream of the exhaust gas throttle valve.

Abstract: Engine exhaust system for an internal combustion engine, the engine exhaust system comprising an exhaust conduit (14) connected to an engine (30), an exhaust gas return conduit (32,33) such that at least a part of the exhaust gas can be returned to the engine. The exhaust gas return conduit, at least along a part of its length, is formed with at least two flow paths (48,49). The engine exhaust system further comprises a particle filter arranged in each of the at least two flow paths and at least one cold flame vaporizer (11) in which fuel is partially oxidized in preheated air to form a cold flame gas. The at least one cold flame vaporizer is arranged in fluid communication with all the flow paths such that the cold flame gas can flow through the particle filters, whereby the cold flame gas can be used to regenerate the particle filter in at least one of the exhaust flow paths while, simultaneously, exhaust gas can flow through the other exhaust flow path or exhaust flow paths.

Abstract: A method and an arrangement are provided for maintaining the oxidation of NO to NO2 in an oxidation catalytic converter arranged in a vehicle, the vehicle including an internal combustion engine which in operation emits exhaust gases to an exhaust gas after treatment system including the oxidation catalytic converter. A predetermined quantity of hydrocarbon is delivered to the exhaust gas aftertreatment system or the engine over at least one predetermined time interval for the purpose of maintaining the working temperature or regenerating an exhaust gas aftertreatment unit. The quantity of hydrocarbon is delivered to the exhaust gas aftertreatment system or to the engine through an injection with at least one predetermined fragmentation frequency and an injection period in order to maintain an NO2 production in the exhaust gas aftertreatment system that prevailed immediately prior to said time interval for the hydrocarbon injection.

Abstract: The present invention relates to a latent heat storage device for an exhaust system of a combustion engine, more preferably of a motor vehicle, with at least one hollow space having a storage volume which contains a phase-changing material. The material loading of the latent heat storage device can be reduced if the storage volume is so dimensioned that it comprises a basic volume which the phase-changing material assumes in the solidified state, and an expansion volume, which the phase-changing material additionally assumes in the molten state.

Abstract: An exhaust gas purifying device that is provided in an exhaust passage of an internal combustion engine and purifies exhaust gas, and a reducing agent injection valve that injects fuel to a position upstream of the exhaust gas purifying device in the exhaust passage are provided. A timing for injecting fuel from the reducing agent injection valve is adjusted to match a timing when exhaust gas discharged on an exhaust stroke of each of cylinders of the internal combustion engine reaches the position to which fuel is injected from the reducing agent injection valve. A single injection amount is changed in accordance with a condition of combustion exhaust gas that is discharged on one exhaust stroke of each of the cylinders and reaches the point to inject fuel.

Abstract: A diagnostic method is provided for a particle filter arranged in exhaust-gas flow of an internal combustion engine. A particle concentration is detected by a particle sensor positioned downstream of the particle filter. The combustion-relevant engine parameters are briefly changed by an engine controller in such a way that an untreated emissions concentration from the engine is significantly increased. A filter fault message is output if the detected associated measurement values of the particle concentration exceed a detection threshold value of the particle sensor, which is in particular considerably greater than a predefined, preferably volume-related particle limit value.