Methods and systems are provided for heating a catalyst via a catalyst heater are presented. In one example, the catalyst may be heated to provide a minimum amount of time for the catalyst to reach a threshold temperature. In another example, the catalyst heater may be heated to minimize an amount of power that is used to heat the catalyst.

Systems and methods for operating an internal combustion engine that is included in a hybrid vehicle are described. In one example, the internal combustion engine is operated in a two stroke mode during cold starting to increase mass flow to an electrically heated catalyst so that engine emissions may be reduced.

A method, controller, and internal combustion engine including the controller and operable in accordance with the method by: determining a temperature of a working liquid in an engine block circuit (31, 35) of the internal combustion engine (10), the working liquid comprising a cooling liquid or a lubrication liquid; operating the internal combustion engine (10); engaging a thermal load responsive to the temperature of the liquid being below a first temperature threshold, wherein engaging the thermal load comprises at least one of increasing a pumping load of the internal combustion engine (10), or changing an air/fuel ratio, thereby adding heat to the engine block circuit (31, 35); controlling the thermal load as a function of the temperature of the liquid; and disengaging at least a portion of the thermal load responsive to the temperature of the liquid being above the low temperature limit.

A control device and a control method for a multi-cylinder internal combustion engine including a post-processing device are provided. The control device includes an electronic control unit executing a temperature raising process of raising the temperature of the post-processing device and a recovery-time process. The temperature raising process includes a stopping process and a rich process. In the stopping process, supply of fuel to several of cylinders is stopped. In the rich process, the air-fuel ratio of an air-fuel mixture for different ones of the cylinders other than the several cylinders is made lower than the stoichiometric air-fuel ratio. In the recovery-time process, the concentration of unburned fuel in exhaust gas discharged to the exhaust passage is made higher than an equivalent concentration, when the temperature raising process is stopped. The equivalent concentration is the concentration of unburned fuel being just enough to react with oxygen in the exhaust gas.

An exhaust purification apparatus for an internal combustion engine has an exhaust purification catalytic agent disposed in an exhaust passage. The exhaust purification apparatus for the internal combustion engine has an exhaust throttle valve, an actuator, and a controller. The exhaust throttle valve is arranged upstream of the exhaust purification catalytic agent in the exhaust passage and changes a passage sectional area of the exhaust passage. The actuator operates the exhaust throttle valve to be open and closed. The controller controls the exhaust throttle valve to be open and closed through the actuator. The controller decreases an opening degree of the exhaust throttle valve to narrow the passage sectional area of the exhaust passage upon a heating request for heating the exhaust purification catalytic agent.

A method and system for non-uniform catalyst heating for reducing exhaust gas emissions when the catalyst is below a predetermined light off temperature is provided. The method includes providing a catalyst formed of a plurality of electrically conductive subsections and at least one catalyst heating device that is operable to heat at least one of the plurality of electrically conductive subsections of the catalyst to form at least one predetermined non-uniform heating pattern. A heater control module is provided for controlling the operation of the at least one catalyst heating device. If the engine is in a cold start condition, then the heater control module causes the at least one catalyst heating device to heat at least one of the electrically conductive subsections of the catalyst to obtain a first predetermined non-uniform heating pattern.

Methods and systems are provided for an exhaust system. In one example, the exhaust system includes an aftertreatment device and a recirculation passage. A recirculation valve is positioned in the recirculation passage and configured to control an amount of recirculated exhaust gas flowing through the recirculation passage to the aftertreatment device. The exhaust system further includes a diverter valve configured to control a flow of engine exhaust gases to different portions of a catalyst of the aftertreatment device.

An ECM executes a catalyst early activation control at cold start of an engine such that the activation of a catalyzer is promoted by opening a WGV. Further, the ECM performs a diagnosis process of, during execution of the catalyst early activation control, repeating opening and closing of the WGV with a given period and diagnosing whether or not the WGV is stuck, based on whether or not a fluctuation component with the same period as the period of the opening and closing of the WGV is included in output from an intake manifold pressure sensor during the repetition.

Fuel in a fuel tank is supplied by a low-pressure pump to intake passage injectors mounted on an intake manifold via a low-pressure fuel supply pipe and a low-pressure fuel distribution pipe. A high-pressure pump is provided on the low-pressure fuel supply pipe. The pressure of the fuel is boosted by the high-pressure pump, and then is supplied to in-cylinder injectors via a high-pressure fuel distribution pipe. In an intake passage injection (MPI) mode, excitation of a solenoid is stopped and operation of an electromagnetic spill valve is stopped so as reduce vibration and noise caused by the seating of the electromagnetic spill valve in a valve seat.

An air supply device for an electrically heated catalyst is proposed. The device includes an electronic supercharger fluidly connected to an intake manifold, an intake valve fluidly connected to the electronic supercharger, an exhaust valve fluidly connected to an exhaust manifold of the engine, an electrically heated catalyst fluidly connected to the exhaust manifold and positioned in a front end of a catalyst part, and a controller configured to control driving of the electronic supercharger and an opening degree of each of the intake valve and the exhaust valve. The controller controls the electronic supercharger based on a door opening condition in a cold operation and switches the intake valve to an advance state and the exhaust valve to a retard state, thus heating the electrically heated catalyst.