Valve device, in particular for an exhaust gas section of an internal combustion engine, includes a valve housing with an inlet and outlet, a valve seat arranged between the inlet and outlet and having a valve opening, closeable by a valve closing member pressed against the valve seat by a predetermined force, and a diaphragm acting on the valve closing member. A first control chamber is separated from a second control chamber by the diaphragm so that the valve is switched by a pressure difference between the first control chamber and second control chamber. For reliable opening even under adverse operating conditions, the diaphragm is connected to the valve closing member, at least over a partial range of a possible stroke of the valve closing member, via a gear mechanism to translate movement of the diaphragm into movement of the valve closing member at a lower speed.

A vehicle control system includes: a fuel control module configured to control gasoline fueling of an engine in open loop based on a target engine lambda; and a burner control module configured to control gasoline fueling of a burner based on (a) a target lambda input to a three-way catalyst (TWC) in an exhaust system of the engine and (b) a lambda of exhaust input to the TWC. The burner is coupled to the exhaust system between (a) an output of the engine and (b) an input to the TWC.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

Methods and systems for operating an engine that includes a controller and a NOx sensor are described. In one example, output of the NOx sensor is selectively made available to software modules within the controller when an offset in NOx sensor output is not expected. If the offset in NOx sensor output is expected, the NOx sensor output may not be made available to the software modules.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

Methods and systems are provided for an exhaust system. In one example, a method includes heating an aftertreatment device during an engine off. The heating includes utilizing one or more of an injector, a heater, and a recirculation fan.

Methods and systems are provided for routing secondary air to engine an exhaust system during a cold-start condition to reduce tail pipe emissions. In one example, a method may include operating a pump of an evaporative leak check module (ELCM) in a positive pressure mode and routing pressurized air to the exhaust passage upstream of an exhaust catalyst via an air conduit housing a first valve.

An air injection system for an engine includes an exhaust flange formed in a cylinder head integrated with an exhaust manifold, wherein the exhaust manifold is coupled to the exhaust flange, an air injection nozzle provided on the cylinder head or the exhaust manifold, a valve configured to control air supplied to the air injection nozzle, and a controller configured to control the valve, wherein the controller is configured to control the valve and inject air through the air injection nozzle when an exhaust-gas temperature reaches a predetermined combustion temperature in an initial start stage of the engine.