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 desired position of the bypass valve based on the vessel location and/or a current time. If the bypass valve is not in the desired position, an instruction is generated to adjust the bypass valve to the desired position to change a noise level generated by the adjustable exhaust system.

Methods and systems are provided for user controlled engine revving. In one example, the engine may be revved to a peak speed according to a target revving sequence in response to a user-initiated command. A revving sound may be provided in response to an input device, without demanding manual depression of an accelerator pedal.

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.

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.

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.

An exhaust system capable of diluting a hydrogen gas to a concentration below the lower explosive limit without requiring a large amount of dilution gas while preventing an increase in a pressure of an exhaust gas in a buffer tank is disclosed. The exhaust system performs, when a main valve disposed in an exhaust line is closed, an initial exhaust operation in which a gas heavier than the hydrogen gas is discharged from a lower part of a buffer tank while an inlet valve disposed in an inlet line and a first outlet valve disposed in an outlet line are opened to introduce the exhaust gas from an equipment in a tangential direction of a buffer tank. Next, the exhaust system performs a hydrogen-gas discharge operation in which the inlet valve and the first outlet valve are closed, and the a bypass valve disposed in a bypass line and the second outlet valve disposed in a hydrogen-gas discharge line are opened to discharge the hydrogen gas stayed in an upper part of the buffer tank while flowing the exhaust gas into a bypass line.

Methods and systems are provided for diagnostics of a gasoline particulate filter in an exhaust system. In one example, a method may include indicating degradation of a hose coupled across a particulate filter responsive to a difference between a first differential pressure and a second differential pressure being greater than a threshold, the first differential pressure measured by a differential pressure sensor positioned in the hose responsive to a downstream exhaust tuning valve being fully open, the second differential pressure measured by the differential pressure sensor responsive to the exhaust tuning valve being fully closed.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.

An exhaust gas aftertreatment system for an internal combustion engine is disclosed. In one embodiment, the system has a first aftertreatment element including a first inlet region and a first outlet region, and a second aftertreatment element including a second inlet region and a second outlet region The first outlet region is connected to the second inlet region via at least one connection section, and the at least one connection section extends outside the first aftertreatment element. At least parts of the first inlet region and of the second inlet region are arranged in a common distributor housing.