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.

Systems and methods for operating an engine that includes an exhaust tuning valve in its exhaust system are described. In one example, a position of the exhaust tuning valve may be adjusted to reduce a possibility of the exhaust tuning valve becoming stuck due to freezing water. In particular, the exhaust tuning valve may be cycled as ambient temperature approaches a temperature at which water freezes.

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 device may include a first pipe and a second pipe defining a first and second flow path through a muffler body. The second pipe is a muffled flow path and includes a plurality of perforations configured to allow exhaust gasses flowing therethrough to disperse out of the second pipe and into an interior volume of the muffler body. A device may include a valve disposed in the first flow path, wherein when the valve is in an open position exhaust gases flow through the first flow path and when the valve is in a closed position exhaust gases flow through the second flow path. A device may include a controller configured to selectively cause the valve to transition from the open position to the closed position.

Methods and systems are provided for adjusting a position of an exhaust valve that regulates engine exhaust noise. In one example, the position of the exhaust valve is adjusted according to a distance between a first vehicle and a second vehicle. The exhaust valve may be adjusted to reduce an exhaust noise level when the distance between the first vehicle and the second vehicle is less than a threshold distance.

An exhaust flap for an exhaust system of a motor vehicle, which has an internal combustion engine and an electronic processing device for a closed-loop control of the internal combustion engine, has a valve element, an actuator for moving the valve element, and a dedicated electronic processing device. The dedicated electronic processing device is configured to receive a first signal which is provided by the electronic processing device of the motor vehicle and which characterizes a first position of the valve element, generate a second signal which characterizes a second position of the valve element as a function of the received first signal, and transmit the second signal to the actuator. The actuator moves the valve element into the second position based on the received second signal.

Methods and systems are provided for diagnostics of an exhaust tuning valve during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled while the position of the exhaust is varied and an intake air flow is estimated at each position of the exhaust tuning valve. The exhaust tuning valve may be diagnosed based on a change in air flow with the variation in the position of the exhaust tuning valve.

A muffler for an exhaust system of an internal combustion engine includes a muffler housing (14) and at least one exhaust gas pipe group (19). The at least one exhaust gas pipe group (19) includes an outlet pipe (20) open towards an expansion chamber (26) formed in the muffler housing (14). Exhaust gas introduced via the at least one exhaust gas pipe group (19) leaves the muffler housing (16) via the outlet pipe (20). A first inlet pipe (38), of the at least one exhaust gas pipe group (19), has an inlet pipe end area (40), which is inserted into the outlet pipe (20) and extends in the outlet pipe (20). A second inlet pipe (48), of the at least one exhaust gas pipe group (19), is open towards the expansion chamber (26).

A muffler for use with an internal combustion engine is provided. The muffler includes a first tube configured to receive a first exhaust stream. The first tube includes a first inlet portion, a first outlet portion spaced apart from the first inlet portion, and a first intermediate portion extending between the first inlet portion and the first outlet portion. The muffler also includes a second tube configured to receive a second exhaust stream. The second tube includes a second inlet portion, a second outlet portion spaced apart from the second inlet portion, and a second intermediate portion extending between the second inlet portion and the second outlet portion. The first intermediate portion and the second intermediate portion cross each other, are at least partially stacked on each other, and are in fluid communication with each other.

Methods and systems are provided for an exhaust tuning valve. In one example, a method may include adjusting the exhaust tuning valve in response to a steering wheel angle input. Additionally or alternatively, the position of the exhaust tuning valve may be adjusted differently in response to a same steering wheel angle input during different driving behaviors.