An internal combustion engine with a turbocharger includes a catalyst, downstream of a turbine, in an exhaust passage. The internal combustion engine includes a waste gate, and a waste gate valve. The internal combustion engine further includes a flow-adjusting member or a flow-adjusting mechanism. The flow-adjusting member disperses a flow of exhaust gas from the waste gate when the opening degree of the waste gate valve is small and concentrates the flow when the opening degree of the waste gate valve is large. The flow-adjusting mechanism switches between a dispersed state in which the flow is dispersed and a concentrate state in which the flow is concentrated.

An exhaust gas purification system of an internal combustion engine according to the present invention includes: processing means for executing at least one of a process of increasing an air-fuel ratio of an air-fuel mixture burned in the internal combustion engine and a process of increasing EGR gas recirculated by an EGR apparatus, when increasing a NO.sub.2 proportion in exhaust gas; and control means for controlling the processing means so that an increase in the air-fuel ratio becomes larger, and an increase in the EGR gas becomes smaller when a temperature of the exhaust gas purification apparatus is high as compared to when the temperature of the exhaust gas purification apparatus is low.

A method for operating a multiple cylinder diesel engine system in a thermal management mode comprises monitoring an aftertreatment temperature, monitoring operating conditions, and determining that the aftertreatment temperature is below an ideal temperature. Fuel injected in to firing cylinders of the multiple cylinder diesel engine can be increased until the aftertreatment temperature is above the ideal temperature, which can comprise selecting a get hot mode that provides an optimal heat transfer rate for transferring heat exhausted from the multiple cylinder diesel engine to the aftertreatment. When the aftertreatment temperature is above the ideal temperature, and when the multiple cylinder diesel engine system is operating within at least one threshold range, cylinder deactivation mode can be entered in at least one cylinder of the multiple cylinder diesel engine. The method can modulate the number of cylinders in cylinder deactivation mode to maintain the aftertreatment temperature above the ideal temperature.

An apparatus and method for controlling engine start/stop operations based at least in part on considerations relating to the thermal management of an exhaust gas after-treatment system. A control system may monitor and/or predict conditions and/or properties of the after-treatment system, including conditions related to the thermal management of a selective catalytic reduction system and the properties of an exhaust gas stream that has been released from an internal combustion engine and into the after-treatment system. Such conditions may be evaluated in determining whether the thermal management of the after-treatment system is at, or will be in, a condition that may accommodate a start/stop operation of the internal combustion engine with minimal, if any, adverse impact on the thermal management of the after-treatment system. Such an evaluation may, in at least certain situations, provide at least a consideration as to whether to de-activate or activate start/stop operations.

An exhaust gas control apparatus includes a first catalyst, a filter, and an electronic control unit. The electronic control unit is configured to alternately execute lean control and rich control multiple times. The lean control is control for, over a period longer than a period from when a target air-fuel ratio is set to a predetermined lean air-fuel ratio until an air-fuel ratio of exhaust gas flowing out from the first catalyst becomes greater than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined lean air-fuel ratio. The rich control is control for, over a period longer than a period from when the target air-fuel ratio is set to a predetermined rich air-fuel ratio until the air-fuel ratio of exhaust gas flowing out from the first catalyst becomes smaller than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined rich air-fuel ratio.

A control apparatus of an engine including intake and exhaust valves and a variable valve timing mechanism for varying open and close timings is provided. The apparatus includes a processor configured to execute an increasing amount controlling module for performing a fuel amount increase control in which a fuel injection amount is increased to decrease an exhaust gas temperature, and a valve controlling module for controlling, via the variable valve timing mechanism, an overlapping period in which the intake and exhaust valves are both opened on intake stroke. When the increasing amount controlling module performs the increase control, based on an increase of a temperature of the exhaust gas in the increase control, the valve controlling module determines whether a protection for an exhaust system component is required, and if the protection is determined to be required, the valve controlling module shortens the overlapping period.

Methods for mitigating over-temperature during an exhaust gas system particulate filter device regeneration are provided. The exhaust gas system can include an exhaust gas stream supplied by an exhaust gas source to a particulate filter device through an exhaust gas conduit. The methods can include detecting an over-temperature during a particulate filter regeneration, initiating one or more first mitigation strategies, and shutting down the exhaust gas source. The one or more first mitigation strategies can include inhibiting the particulate filter device regeneration, altering the exhaust gas source operating parameters, and activating a cooling fan. The exhaust gas source can include an internal combustion engine configured to power a vehicle, and the operating parameters can be altered by a torque limiter.

When the temperature of the exhaust gas flowing into an NSR catalyst exceeds a specific threshold temperature that is determined on the basis of the cetane number of fuel in such a way that the specific threshold temperature is set lower when the cetane number of the fuel is low than when it is high, fuel is supplied to the exhaust gas by fuel supply device to perform an NO.sub.X reduction process for the NSR catalyst. If the quantity of heat generated in the NSR catalyst per unit time is smaller than a specific value while the NO.sub.X reduction process is being performed, the NO.sub.X reduction process in progress is suspended, and the NO.sub.X reduction process is performed later on when the temperature of the exhaust gas flowing into the NSR catalyst exceeds an updated threshold temperature higher than the specific threshold temperature.

A method (100) and apparatus (10-1) for carrying out the method of mitigating fuel in oil in an internal combustion engine of a hybrid electric vehicle. the method comprising: detecting one or more of a catalyst temperature and a turbine temperature (110); and when the one or more of the catalyst temperature and the turbine temperature exceeds a first temperature threshold, limiting engine torque below a threshold engine torque required for the operation of an enrichment phase of engine operation (120). wherein the enrichment phase of engine operation provides a lambda value less than 1.

Methods and systems are provided for addressing pre-ignition occurring while operating with blow-though air delivery. A variable cam timing device used to provide positive intake to exhaust valve overlap is adjusted in response to an indication of pre-ignition to transiently reduce valve overlap. Pre-ignition mitigating load limiting and enrichment applied during a blow-through mode is adjusted differently from those applied when blow-through air is not being delivered.