Methods and systems are provided for regenerating a particulate filter positioned in an exhaust system of an engine of a vehicle. In one example, a method comprises obtaining a first air flow in an intake of the engine and obtaining a second air flow in the intake of the engine, where regeneration of the particulate filter is conducted in response to the first air flow differing from the second air flow by at least a threshold amount, where the first air flow and the second air flow comprise air flow routed from the exhaust system to the intake of the engine. In this way, the particulate filter may be regenerated under conditions where a loading state of the particulate filter is not known.

A method includes determining that at least one diesel emissions fluid (DEF) doser of an exhaust aftertreatment system is likely frozen based on at least one of an ambient air temperature or a DEF source temperature; operating an engine in a cylinder cutout mode in response to the determination that the at least one DEF doser is likely frozen; and, discontinuing the cylinder cutout mode in response to determining that the at least one DEF doser is in a predefined condition.

A controller for a hybrid electric vehicle including an internal combustion engine is provided. The internal combustion engine includes a filter arranged in an exhaust passage collect particulate matter from exhaust gas. The controller executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process uses a fuel cutoff process when deceleration of the hybrid electric vehicle is required. The second deceleration control process does not use the fuel cutoff process when deceleration of the hybrid electric vehicle is required. The selection process selects execution of the second deceleration control process when a PM deposition amount is greater than or equal to a threshold value and selects execution of the first deceleration control process when the PM deposition amount is less than the threshold value.

Methods and systems are provided for cylinder deactivation to reduce tailpipe emissions and increase exhaust temperature. In one example, a method may include operating a first set of cylinders in a first combustion cycle over modified eight strokes and a second set of cylinders in a second combustion cycle over modified four strokes. Each cylinder in the first set of cylinders may be selectively deactivated via a variable displacement engine (VDE) mechanism while each cylinder in the second set of cylinders may be selectively deactivated via an active decompression technology (ADT) mechanism.

The invention relates to an internal combustion engine system (100), comprising: —an internal combustion engine (2) comprising a cylinder block (3) housing a plurality of cylinders (4), a first intake manifold (6a) connected to a first group of cylinders (4a) a second distinct intake manifold (6b) connected to a second group of cylinders (4b) and a first, respectively a second, exhaust manifold (8a, 8b) for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders (4a, 4b); —an air inlet line (10); —an EGR line (20) connected to the first and second exhaust manifolds (8a, 8b); wherein the internal combustion engine system is operable in at least two operating modes, respectively a normal operating mode in which all cylinders are supplied with fuel and a regeneration operating mode, in which the cylinders of the first group of cylinders (4a) are no longer supplied with fuel, characterized in that: —the system also includes a mixing unit (30) comprising a four-way valve, said four-way valve (30) having a first inlet (31) connected to the EGR line (20), a second inlet (32) connected to the air inlet line (10), a first outlet (33) connected to the first intake manifold (6a) and a second outlet (34) connected to the second intake manifold (6b); —the four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold (6a) and to the second intake manifold (6b) have approximately the same proportion of exhaust gas and so that, in said regeneration operating mode, the intake gas supplied to the first intake manifold (6a) only includes exhaust gas.

A controller for a hybrid electric vehicle including an internal combustion engine is provided. The internal combustion engine includes a filter arranged in an exhaust passage collect particulate matter from exhaust gas. The controller executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process uses a fuel cutoff process when deceleration of the hybrid electric vehicle is required. The second deceleration control process does not use the fuel cutoff process when deceleration of the hybrid electric vehicle is required. The selection process selects execution of the second deceleration control process when a PM deposition amount is greater than or equal to a threshold value and selects execution of the first deceleration control process when the PM deposition amount is less than the threshold value.

A system includes an exhaust aftertreatment system in exhaust gas receiving communication with an engine including a plurality of cylinders where the engine is structured to operate according to low load conditions and where a controller is structured to determine that at least one diesel emissions fluid (DEF) doser is frozen based on at least one of an ambient air temperature and a DEF source temperature. The controller is structured to operate the engine according to a skip-fire mode in response to a DEF flag indicating that the at least one DEF doser is frozen. The skip-fire mode comprises firing a portion of the plurality of cylinders that is less than a total amount of cylinders of the plurality of cylinders. The controller is structured to discontinue the skip-fire mode in response to determining that the at least one DEF doser is likely thawed.

A method (200) for operating an exhaust gas burner (120) in an exhaust section (102) of an internal combustion engine (110), comprising introducing a purging fluid comprising at least air (20) into the exhaust gas burner (120) during a purging operating phase (205), which lies outside the time of a normal operating phase (201) of the exhaust gas burner (120), and discharging a discharge mixture formed using the purging fluid from the exhaust gas burner (120), wherein the exhaust gas burner (120) is operated for the purpose of heating a component (130, 150) of the exhaust section (102) to its operating temperature during the normal operating phase (201). A processor unit (140) and a computer program for carrying out such a method (200) are furthermore proposed.

A hybrid vehicle includes a multi-cylinder engine, an exhaust gas control apparatus including a catalyst for removing exhaust gas from the multi-cylinder engine, an electric motor, and a control device configured to execute catalyst temperature increase control for stopping fuel supply to at least one cylinder and making an air-fuel ratio in each of remaining cylinders rich in a case where a temperature increase of a catalyst is requested during a load operation of the multi-cylinder engine, execute control such that an electric motor supplements insufficient drive power due to the execution of the catalyst temperature increase control, and change the air-fuel ratio in at least one of the remaining cylinders to a lean side after a temperature of the exhaust gas control apparatus becomes equal to or higher than a determination threshold value during the execution of the catalyst temperature increase control.

A system and method for a variable displacement internal combustion engine using different types of pneumatic cylinder springs on skipped working cycles to control engine and aftertreatment system temperatures are described. The system and method may be used to rapidly heat up the aftertreatment system(s) and/or an engine block of the engine following a cold start by using one or more different types of pneumatic cylinder springs during skipped firing opportunities. By rapidly heating the aftertreatment system(s) and/or engine block, noxious emissions such as hydrocarbons, carbon monoxide, NO.sub.x and/or particulates, following cold starts are significantly reduced.