When a temperature of a catalyst in an exhaust emission control device mounted in an exhaust system of an engine is equal to or higher than a predetermined temperature at a time of a request for stopping the engine, a hybrid vehicle including the engine and a motor continues fuel injection of the engine until satisfaction of a predetermined condition and stops fuel injection of the engine on satisfaction of the predetermined condition. When the temperature of the catalyst is lower than the predetermined temperature at the time of the request for stopping the engine, on the other hand, the hybrid vehicle immediately stops fuel injection of the engine.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, each of a first valve positioned in an exhaust gas recirculation (EGR) passage, the EGR passage coupled between the intake passage and the first exhaust manifold coupled to a first set of cylinder exhaust valves, and a second valve positioned in a flow passage coupled between the first exhaust manifold and the exhaust passage may be adjusted based on a measured pressure in the first exhaust manifold.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, in response to an intake throttle being at least partially closed, intake air may be routed from the intake passage to the first exhaust manifold via an exhaust gas recirculation (EGR) passage where the intake air may be heated via an EGR cooler. The heated intake air may then be routed to an intake manifold, downstream of the intake throttle, via a flow passage coupled between the first exhaust manifold and the intake manifold.

A GDCI engine control system includes a heated catalyst in an engine exhaust port that is in close proximity to a combustion chamber and is used to heat rebreathed exhaust gases. The engine more quickly reaches operating temperatures, and emissions are reduced during cold running.

A vehicle hybrid powertrain includes an internal combustion engine: an electrical drivetrain: a selective catalytic reduction (SCR) device coupled to receive exhaust from the internal combustion engine: a fuel burner; and a control system that controls heat applied to the SCR device including by controlling the fuel burner and the internal combustion engine.

In a method of reducing pollutants of a combustion engine, exhaust gas, generated by a cylinder of the combustion engine, is fed to an exhaust gas aftertreatment system as a function of a predefined condition solely via a first exhaust channel which communicates with a first one of first and second exhaust valves of the cylinder. The first exhaust channel is hereby coated, at least in part, by a thermally insulating layer selected such that a heat input is transmitted to the exhaust gas aftertreatment system which heat input is greater than a heat input in a second exhaust channel communicating with a second one of the first and second exhaust valves. The predefined condition is defined as a function of a coolant temperature of the combustion engine.

A method of controlling temperature of an engine aftertreatment system includes directing an exhaust heating device in an engine aftertreatment system to apply heat to the engine aftertreatment system; opening at least one of one or more intake valves and one or more exhaust valves of an engine coupled to the engine aftertreatment system; and pulsing, by an engine starter of the engine, the engine to generate airflow from the engine that moves the applied heat from the exhaust heating device downstream the engine aftertreatment system.

A method for operating an internal combustion engine using an external exhaust-gas recirculation device with a recirculation setting device to set the flow rate of the recirculated exhaust gas and using a closing time setting device to adjust the closing time of the at least one inlet valve of the internal combustion engine. For the reduction of nitrogen oxides emitted by the internal combustion engine, it is possible, by way of the closing time setting device, for a nitrogen oxide reduction cycle to be set in which the at least one inlet valve of the internal combustion engine closes earlier or later than in the basic cycle. If the torque of the internal combustion engine falls below at least a defined torque threshold value, the internal combustion engine is operated in the basic cycle and the recirculation of the exhaust gas is enabled by way of the recirculation setting device, and wherein, if the torque of the internal combustion engine exceeds the defined torque threshold value, the internal combustion engine is operated in the nitrogen oxide reduction cycle and the recirculation of the exhaust gas is blocked by way of the recirculation setting device.

A vehicle hybrid powertrain includes an internal combustion engine; an electrical drivetrain; a selective catalytic reduction (SCR) device coupled to receive exhaust from the internal combustion engine; a fuel burner; and a control system that controls heat applied to the SCR device including by controlling the fuel burner and the internal combustion engine.

A method of operating a vehicle with a hybrid powertrain comprising an electrical drivetrain and an internal combustion engine includes detecting that a temperature of a selective catalytic reduction (SCR) device of an aftertreatment system of the vehicle is below a particular temperature; directing the electrical drivetrain to fulfil a vehicle drive load; and while the electrical drivetrain is fulfilling the vehicle drive load and the temperature of the SCR device is below the particular temperature, operating the internal combustion engine to generate airflow for transport of heat through the aftertreatment system and directing a heat source to raise a temperature through the SCR device of the aftertreatment system. The internal combustion engine can be operated in idle to spin the internal combustion engine to generate the airflow while the electrical drivetrain fulfils the vehicle drive load.