A method of controlling an adjustable exhaust system for a marine engine includes receiving a vessel location of a marine vessel having an adjustable exhaust system and identifying a noise constraint based on the vessel location. A current exhaust mode of the adjustable exhaust system is identified. A determination is then made regarding whether the exhaust system is exceeding the noise constraint based on the current exhaust mode. If the noise constraint is exceeded, an instruction is generated to adjust the adjustable exhaust system to comply with the noise constraint.

A post-treatment system includes two SCRs, a second SCR is connected to a booster in parallel, and a three-way valve is arranged before the second SCR and the booster, such that whether an exhaust gas flows through the second SCR or the booster is controlled by means of controlling the three-way valve. In the case of a low temperature, the three-way valve is controlled to close a branch of the booster, such that the exhaust gas flows through the second SCR and a first SCR that are connected in series, thereby reducing the energy loss caused by the exhaust gas flowing through the booster, and improving the NO.sub.x conversion efficiency in the case of a low temperature. In a case of a high temperature, the three-way valve is controlled to close a by-pass line, such that the exhaust gas flows through the booster and the first SCR.

An engine exhaust system includes a catalytic converter, an exhaust conduit connected upstream of the catalytic converter, and an oxygen sensor extending into the exhaust conduit at a first axial position of the exhaust conduit. A valve is located within the exhaust conduit at the first axial position. The valve includes a movable throttle plate having a bypass notch formed on a periphery of the plate. The valve has an open position, and a closed position in which the bypass notch is placed adjacent to the oxygen sensor to guide exhaust over the oxygen sensor.

Vehicle sound attenuation systems and methods are provided herein. An example method includes determining a triggering event for a vehicle using an advanced driver assisted technology system, and controlling a sound enhancing system of the vehicle in response to the triggering event. Controlling the sound enhancing system may include attenuating engine or exhaust sound produced by the sound enhancing system of the vehicle.

Methods and systems to control a temperature of a selective catalytic reduction catalyst are disclosed. In one example, a diverter valve that includes two butterfly valves that are coupled together via a shaft is adjusted to control a temperature at an inlet of the selective catalytic reduction catalyst so that the selective catalytic reduction catalyst may operate efficiently.

An electric actuator comprises a motor and a plate, wherein the motor has an electric contact in electrical contact with the plate. An intermediate shaft is in contact with the plate. A controller is fixed to an upper part of the actuator. The controller has an electrical output electrically communicating with the electric contact of the motor through the intermediate shaft and the plate.

Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.

Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.

An improved pipe exhaust cut-out that is adapted to be controllably opened and completely closed thereby sealing the exhaust pipe cut-out. The improved pipe exhaust cut-out incorporates a remotely controlled linear actuator.

A valve for use in an engine exhaust conduit. The valve includes a base portion and a body portion extending from the base portion. The base portion is configured for pivotably mounting the valve within the engine exhaust conduit. The base portion defines a valve pivot axis. The valve is pivotable about the valve pivot axis during use. The body portion has an upstream side and a downstream side opposite the upstream side. The upstream side is exposed, during use, to fluid flow in the engine exhaust conduit. The body portion has a generally pointed shape defining a rounded tip at a location of the body portion furthest from the base portion in a length direction of the valve. The length direction of the valve is generally perpendicular to the valve pivot axis.