An exhaust gas aftertreatment system for an internal combustion engine charged by an exhaust gas turbocharger and spark-ignited by means of spark plugs has a particulate filter and a first three-way catalytic converter downstream from the particulate filter in a position close to the engine in an exhaust gas system connected to an outlet of the internal combustion engine and another three-way catalytic converter arranged in the underbody position of the motor vehicle, downstream from the first three-way catalytic converter. An exhaust gas burner is active from the start of the engine, introducing hot exhaust gas into the exhaust gas system downstream from the particulate filter, in order to heat at least one of the three-way catalytic converts to a light-off temperature, as quickly as possible after the cold start, thereby allowing an efficient exhaust gas aftertreatment. The exhaust gas burner can be switched off when at least one of the two three-way catalytic converters has reached its light-off temperature.

Provided is a diesel engine capable of regenerating a DPF even during no-load and/or light-load operation. In a DPF regeneration process, opening-degree reduction control S2 for an exhaust-air throttle valve is performed after a start condition S1 of the regeneration process of the DPF in which PM is deposited is satisfied. When exhaust air reaches a temperature equal to or higher than a predetermined after-injection permissible temperature TA, after-injection control is subsequently started S5. Post-injection control is started S7 after the exhaust air reaches a temperature equal to or higher than a predetermined post-injection permissible temperature TP by combustion of after-injection fuel. The PM deposited in the DPF is incinerated by the exhaust air increased in temperature by catalytic combustion of post-injection fuel in a valve downstream-side DOC.

Provided are a method and an ICE system, including an internal combustion engine including a first and a second set of cylinders. A first and a second EGR valve control flow of exhaust gas from the cylinders to an EGR conduit. A controller controls the closing of the second EGR valve, thereby preventing flow of exhaust gas from the second set of cylinders to the EGR conduit. The second EGR valve is upstream of a turbine. The controller is configured to activate a fuel injector for late post injection of fuel into the second set of cylinders when the second EGR valve is closed, so that at least a part of the fuel that exits the second set of cylinders is uncombusted. An exhaust gas aftertreatment system receives and treats exhaust gas which is not recirculated in the EGR conduit, and includes an oxidation catalyst for combustion.

Disclosed is a four-stroke direct injection engine comprising a camshaft, and exhaust valve, and a control system. The control system is configured to change the timing of the camshaft to advance a closing of the exhaust valve, control a first fuel injection step during a compression stroke of the piston, control a second fuel injection step during a power stroke of the piston, and control a third fuel injection step, after the second fuel injection step, during the power stroke of the piston.

A vehicle includes an exhaust passage including an exhaust cleaner, an engine coupled to the exhaust passage, fuel injection valves, and a control device. The fuel injection valves are respectively provided in cylinders of the engine and inject fuel into the cylinders. The control device performs, after main-injection, post-injection control that causes the fuel injection valves to perform post-injection. The control device determines a fuel injection amount for single-time post-injection performed by each fuel injection valve such that the fuel injection amount for the single-time post-injection is greater than a fuel injection amount when the post-injection is performed in every combustion cycle in all the cylinders. The control device performs the post-injection control such that how many times the post-injection is performed is less than how many times the post-injection is performed in a case in which the post-injection is performed in every combustion cycle in all the cylinders.

A controller for controlling regeneration in an aftertreatment system comprising a first leg and a second leg is configured to: determine whether regeneration is permitted by the engine based on engine operating parameters; in response to regeneration being permitted, determine whether regeneration is required in at least one of the first leg or the second leg based on operating parameters of the first leg and the second leg, and whether regeneration is inhibited in either the first leg or the second leg; and in response to determining that (i) regeneration is required in at least one of the first or second leg, and (ii) regeneration is not inhibited in either the first or the second leg, cause insertion of hydrocarbons into the engine to thereby increase the temperature of the exhaust gas to a target temperature and cause regeneration in each of the first and second leg.

An exhaust gas control apparatus for an internal combustion engine includes: a catalyst disposed in an exhaust passage of the engine and configured to be able to occlude oxygen; an air-fuel ratio sensor that detects an air-fuel ratio of an out-flow exhaust gas; and an air-fuel ratio control device that controls an air-fuel ratio of an in-flow exhaust gas to a target air-fuel ratio. The device executes air-fuel ratio reduction control in which the target air-fuel ratio is set to a rich setting air-fuel ratio, and corrects a parameter related to the air-fuel ratio reduction control such that an amount of a reducing gas supplied to the catalyst is decreased when a minimum air-fuel ratio obtained when the detected air-fuel ratio is varied to a rich side is richer than the rich setting air-fuel ratio or an average value of detected air-fuel ratios of the in-flow exhaust gas.

An exhaust gas control apparatus for an internal combustion engine includes: a catalyst disposed in an exhaust passage of the engine and configured to be able to occlude oxygen; an air-fuel ratio sensor that detects an air-fuel ratio of an out-flow exhaust gas; and an air-fuel ratio control device that controls an air-fuel ratio of an in-flow exhaust gas to a target air-fuel ratio. The device executes air-fuel ratio reduction control in which the target air-fuel ratio is set to a rich setting air-fuel ratio, and corrects a parameter related to the air-fuel ratio reduction control such that an amount of a reducing gas supplied to the catalyst is decreased when a minimum air-fuel ratio obtained when the detected air-fuel ratio is varied to a rich side is richer than the rich setting air-fuel ratio or an average value of detected air-fuel ratios of the in-flow exhaust gas.

An engine controller controlling an engine including an occlusion reduction catalyst in an exhaust device includes a fuel injection controller that controls a fuel injection amount of an injector, an EGR controller that controls an EGR device, a sulfur purge determiner that determines whether sulfur purging of the catalyst is to be performed, and a sulfur purge controller that executes sulfur purge control if the sulfur purging is performed. The sulfur purge control involves performing a fuel injection to achieve a rich air-fuel ratio at an inlet of the catalyst and prohibiting the exhaust-gas introduction. The sulfur purge controller executes sulfur-purge standby control when a sulfur-purge standby condition is satisfied, and resumes the sulfur purge control when the condition becomes non-satisfied after starting the sulfur-purge standby control. The sulfur-purge standby control involves performing the fuel injection to nearly achieve a stoichiometric air-fuel ratio and prohibiting the exhaust-gas introduction.

A vehicle includes an exhaust passage including an exhaust cleaner, an engine coupled to the exhaust passage, fuel injection valves, and a control device. The fuel injection valves are respectively provided in cylinders of the engine and inject fuel into the cylinders. The control device performs, after main-injection, post-injection control that causes the fuel injection valves to perform post-injection. The control device determines a fuel injection amount for single-time post-injection performed by each fuel injection valve such that the fuel injection amount for the single-time post-injection is greater than a fuel injection amount when the post-injection is performed in every combustion cycle in all the cylinders. The control device performs the post-injection control such that how many times the post-injection is performed is less than how many times the post-injection is performed in a case in which the post-injection is performed in every combustion cycle in all the cylinders.