Abstract: A controller for an internal combustion engine is configured to control the internal combustion engine. The internal combustion engine includes an in-cylinder injection valve, an ignition device, an exhaust passage, and a three-way catalyst. The controller includes a fuel introduction processor configured to execute a fuel introduction process of introducing air-fuel mixture of fuel and air, which has been introduced into a cylinder, into the exhaust passage without burning the air-fuel mixture in the cylinder. The fuel introduction processor is configured to execute the fuel introduction process in a state in which only a port injection valve of the in-cylinder injection valve and the port injection valve performs fuel injection.

Abstract: A controller for an internal combustion engine includes a fuel introduction process of introducing an air-fuel mixture containing fuel injected by a fuel injection valve into an exhaust passage without burning the air-fuel mixture in a cylinder. The fuel introduction processor is configured to perform, during the execution of the fuel introduction process, a determination process of determining whether afterfire, in which the air-fuel mixture burns at an upstream side of a three-way catalyst device in the exhaust passage, has occurred and a stopping process of stopping the fuel introduction process when determining in the determination process that the afterfire has occurred.

Abstract: An engine controller executes a fuel introduction process of introducing, in a state in which the crankshaft of an internal combustion engine is rotating, air-fuel mixture that contains fuel injected by a fuel injection valve into the exhaust passage without burning the air-fuel mixture in the cylinder. When the oxygen concentration of exit gas that has passed through a three-way catalyst decreases during the execution of the fuel introduction process, the engine controller executes a stopping process of stopping the fuel introduction process.

Abstract: A variable valve timing apparatus for an internal combustion engine, including: an actuator that activates a variable valve timing mechanism; a detection unit that detects a driving position of the actuator; a control unit that drive-controls the actuator, and when a predetermined execution condition is established, executes one of a first initialization process and a second initialization process that match the driving position of the actuator detected by the detection unit with an actual driving position of the actuator; and an abnormality determination unit that determines whether or not an abnormality is present in the driving position detected by the detection unit and stores an abnormality history after determining that an abnormality is present. The control unit executes the first initialization process when the abnormality history is stored and the second initialization process when the abnormality history is not stored.

Abstract: A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

Abstract: A control apparatus for an internal combustion engine includes an ECU configured to: determine whether a temperature-increasing process is being executed; calculate a target value of a parameter correlated with a difference between a rich air-fuel ratio and a lean air-fuel ratio achieved in the temperature-increasing process, based on an operating state of the internal combustion engine; calculate, as an upper limit, a value of the parameter required to increase the temperature of the catalyst to a predetermined upper limit temperature; determine whether the target value is equal to or lower than the upper limit; adjust the parameter used in the temperature-increasing process to the target value when the target value is determined to be equal to or lower than the upper limit; and adjust the parameter used in the temperature-increasing process to the upper limit when the target value is determined to be higher than the upper limit.

Abstract: In a control apparatus for an internal combustion engine, The ignition timing in a rich-cylinder is corrected toward a retardation side from a theoretical-MBT such that the torque generated in the rich-cylinder exceeds a torque generated in the rich-cylinder at the theoretical-MBT, and the ignition timing in a lean-cylinder is corrected toward an advancement side from the theoretical-MBT such that the torque generated in the lean-cylinder exceeds a torque generated in the lean-cylinder at the theoretical-MBT, when a temperature raising process is being executed, and the ignition timing in the rich-cylinder is corrected further toward the retardation side such that the torque generated in the rich-cylinder becomes equal to or smaller than a maximum theoretical generated torque and equal to or larger than the torque generated in the lean-cylinder at the theoretical-MBT, when the temperature raising process is being executed and the engine is in a low-load operating state.

Abstract: A controller for an internal combustion engine includes processing circuitry. The processing circuitry is configured to execute a dither control process under a condition in which a request for executing a regeneration process of a filter is made. The processing circuitry is further configured to execute a fuel cutting process stopping fuel injection performed by fuel injection valves under a condition in which an accelerator operation amount is zero and a prohibition process prohibiting the fuel cutting process under a condition in which the dither control process is executed.

Abstract: A CPU operates a purge valve to control the amount of fuel vapor that flows into an intake passage from a canister. If there is a requirement for increasing the temperature of a three-way catalyst, the CPU executes dither control in which the air-fuel ratio of one of cylinders #1 to #4 is made richer than the stoichiometric air-fuel ratio, and the air-fuel ratio of the remaining cylinders is made leaner than the stoichiometric air-fuel ratio. The CPU executes the dither control and performs feedforward correction of the distribution variation of the fuel vapor to the cylinders #1 to #4 if the amount of fuel vapor from the canister to the intake passage is greater than zero.

Abstract: A controller for an internal combustion engine includes processing circuitry configured to execute: a dither control process of operating fuel injection valves to designate at least one of cylinders as a lean combustion cylinder, in which an air-fuel ratio is leaner than a stoichiometric air-fuel ratio, and to designate at least another one of the cylinders as a rich combustion cylinder, in which an air-fuel ratio is richer than the stoichiometric air-fuel ratio; and an idle-time limiting process of causing an absolute value of a difference between the air-fuel ratio in the lean combustion cylinder and the air-fuel ratio in the rich combustion cylinder to be smaller when the internal combustion engine is idling than when the internal combustion engine is not idling.

Abstract: A temperature estimation module applied to a control apparatus for an internal combustion engine is configured to execute a virtual temperature estimation process that estimates a virtual temperature, which is a temperature of an exhaust purifying device under an assumption that a dither control process is not executed, based on an operation point of the internal combustion engine during execution of the dither control process. The temperature estimation module is further configured to execute an actual temperature estimation process that estimates an actual temperature of the exhaust purifying device based on a difference between the air-fuel ratio of a rich combustion cylinder and the air-fuel ratio of a lean combustion cylinder and based on the operation point of the internal combustion engine during execution of the dither control 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: In the exhaust gas control system, the electronic control unit is configured to execute first air-fuel ratio control for controlling an air-fuel ratio of an air-fuel mixture in a part of cylinders to a lean air-fuel ratio and controlling an air-fuel ratio of an air-fuel mixture in the other part of the cylinders to a rich air-fuel ratio is executed. The electronic control unit is configured to execute second air-fuel ratio control to perform malfunction diagnosis. The electronic control unit is configured to execute second air-fuel ratio control when the execution of the first air-fuel ratio control is interrupted after the temperature of the three-way catalyst becomes equal to or higher than the diagnosis temperature.

Abstract: A controller is configured to execute a dither control process of operating fuel injection valves such that at least one of cylinders is a lean combustion cylinder, in which the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, and at least another one of the cylinders is a rich combustion cylinder, in which the air-fuel ratio is richer than the stoichiometric air-fuel ratio, and a limiting process of limiting the dither control process such that the difference in the air-fuel ratio between the cylinders is smaller in a change period, in which a gear ratio of the multi-speed transmission is changed, than in periods except for the change period.

Abstract: A controller for an internal combustion engine includes a processing circuit that performs a dither control process on condition that a temperature increase request of a catalyst is made. The processing circuit operates fuel injection valves so that during the dither control process, one or more cylinders are lean combustion cylinders in a first period and another one or more cylinders are rich combustion cylinders and so that the average value of an exhaust gas-fuel ratio is a target air-fuel ratio in a second period including the first period. The dither control process is restricted in a manner that, on condition that the rich process is performed, the degree of richening of the richest exhaust gas-fuel ratio of exhaust gas-fuel ratios in the cylinders is reduced.

Abstract: A controller includes an air-fuel ratio control unit that calculates an air-fuel ratio F/B correction value and an air-fuel ratio learning value and corrects an amount of fuel supplied to each cylinder based on the air-fuel ratio F/B correction value FAF and the air-fuel ratio learning value KG. The controller further includes a dither control unit that executes dither control to adjust the amount of fuel supplied to each cylinder, corrected by the air-fuel ratio control unit, so that at least one of the cylinders is set to a rich combustion cylinder and at least a further one of the cylinders is set to a lean combustion cylinder. When the dither control is executed, the air-fuel ratio control unit prohibits execution of air-fuel ratio learning control and executes air-fuel ratio feedback control.

Abstract: A control device for an internal combustion engine includes an electronic control unit configured to perform dither control processing for controlling the fuel injection valve based on a requested injection amount such that a part of cylinders among a plurality of cylinders becomes a lean combustion cylinder and cylinders different from the part of cylinders among the cylinders become a rich combustion cylinder, and restriction processing for, in a case where the requested injection amount is equal to or greater than a first injection amount, making no restriction on the dither control processing, and in a case where the requested injection amount is within a second injection amount range of an injection amount smaller than the first injection amount, restricting the dither control processing to a side where a leaning degree of an air-fuel ratio of a cylinder having a leanest air-fuel ratio among the cylinders decreases.

Abstract: A control device for an internal combustion engine includes an electronic control unit configured to determine whether or not cylinder-specific air-fuel ratio processing is being executed in which an air-fuel ratio of at least one of a plurality of cylinders is controlled to be a rich air-fuel ratio and an air-fuel ratio of at least one of the other cylinders is controlled to be a lean air-fuel ratio. The electronic control unit updates a first learning value in which a result of comparison between a knock strength of the internal combustion engine and a first determination value is reflected when the cylinder-specific air-fuel ratio processing is not being executed. The electronic control unit prohibits updating of the first learning value and calculates a target ignition timing of the internal combustion engine based on the first learning value when the cylinder-specific air-fuel ratio processing is being executed.

Abstract: A misfire determination device for an internal combustion engine includes an electronic control unit configured to determine whether execution of temperature rise processing in which a temperature of a catalyst is raised by an air-fuel ratio of one of the cylinders being controlled to be a rich air-fuel ratio lower than a stoichiometric air-fuel ratio and an air-fuel ratio of each of the other cylinders being controlled to be a lean air-fuel ratio higher than the stoichiometric air-fuel ratio is ongoing, determine occurrence of misfire based on whether a rotation variation amount of the internal combustion engine during non-execution of the temperature rise processing exceeds a first misfire determination value, and determine occurrence of misfire based on whether the rotation variation amount during the execution of the temperature rise processing exceeds a second misfire determination value exceeding the first misfire determination value.

Abstract: A control apparatus for an internal combustion engine includes an ECU configured to: determine whether a temperature-increasing process is being executed; calculate a target value of a parameter correlated with a difference between a rich air-fuel ratio and a lean air-fuel ratio achieved in the temperature-increasing process, based on an operating state of the internal combustion engine; calculate, as an upper limit, a value of the parameter required to increase the temperature of the catalyst to a predetermined upper limit temperature; determine whether the target value is equal to or lower than the upper limit; adjust the parameter used in the temperature-increasing process to the target value when the target value is determined to be equal to or lower than the upper limit; and adjust the parameter used in the temperature-increasing process to the upper limit when the target value is determined to be higher than the upper limit.