A vehicle exhaust device includes a muffler body that has an interior space divided into a plurality of expansion chambers by a partition wall, and an exhaust control valve that switches an exhaust passage in the muffler body. The exhaust passage includes a first exhaust passage and a second exhaust passage. The first exhaust passage connects an upstream end and a downstream end of the muffler body straight. The second exhaust passage passes through the plurality of expansion chambers via a connecting pipe that connects the plurality of expansion chambers. A center of the first exhaust passage is located above a center of the muffler body in a vehicle upper-lower direction, and the second exhaust passage is located below the first exhaust passage.

Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include adjusting engine operation in response to a flow of gases to an intake passage, upstream of a compressor, from a scavenge manifold coupled to scavenge exhaust valves, the flow of gases determined based on a valve opening overlap between the scavenge exhaust valves and intake valves of an engine, the scavenge exhaust valves opened at a different time than blowdown exhaust valves coupled to a blowdown manifold coupled to a turbine.

An engine exhaust control valve of a saddle-riding vehicle is provided with: a valve shaft disposed in an intersecting manner with a center line of a main pipe portion of an engine exhaust pipe; a valve plate mounted on the valve shaft and rotatably positioned within an inner peripheral surface of the main pipe portion; a valve rotational drive portion mounted on one shaft end of the valve shaft; a drive motor for driving the valve rotational drive portion; and a control unit for controlling the drive motor. Protruding portions with which outer peripheral edges of the valve plate are brought into contact at a rotational limit of the valve plate in a closing direction are formed on an inner peripheral surface of the main pipe portion. The above structure provides a high degree of sealing.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, the engine system may be installed in a hybrid vehicle, and, in response to a request to restart the engine while the vehicle is being propelled via motor torque only, the engine may be rotated unfueled via the motor torque at less than cranking speed while at least partially opening a valve disposed in a passage coupled between the first exhaust manifold and the intake passage. In another example, in response to the request to restart the engine, all exhaust valves of a second set of exhaust valves coupled to the second exhaust manifold may be deactivated.

A valve has a housing and a flap. The housing includes a chamber having an inlet, a first outlet, and a second outlet. The flap is rotatably mounted about an axis of rotation within the chamber and is movable between a first position in which the inlet is fluidically connected to the first outlet and the second outlet is closed, a second position, in which the inlet is fluidically connected to the second outlet and the first outlet is closed, and a third position in which the inlet is fluidically connected to the first outlet and the second outlet. The flap has a projection that projects into the second outlet in the first position of the flap. Furthermore, an exhaust branch for an internal combustion engine having a heat exchanger, a bypass, and the valve, and a vehicle having an internal combustion engine and the exhaust branch are provided.

Methods and systems are provided for adjusting operation of a split exhaust engine system based on a total flow of gases through a scavenge exhaust gas recirculation system of the split exhaust engine system. In one example, a method may include adjusting engine operation in response to a flow of gases to an intake passage, upstream of a compressor, from a scavenge manifold coupled to scavenge exhaust valves, the flow of gases determined based on a valve opening overlap between the scavenge exhaust valves and intake valves of an engine, the scavenge exhaust valves opened at a different time than blowdown exhaust valves coupled to a blowdown manifold coupled to a turbine.

The invention relates to an exhaust-gas aftertreatment system for selective catalytic reduction with a plurality of SCR catalytic converters, which exhaust-gas aftertreatment system is able to reduce NOx in a large temperature range and can store SOx. The invention further relates to a method for treating an exhaust gas flow, in which method the exhaust-gas aftertreatment system according to the invention is used. The system comprises a high-temperature SCR catalyst for temperature ranges between 250 C. and 750 C. and a low-temperature SCR catalyst arranged downstream thereof for temperature ranges between 60 C. and less than 250 C. There is a reductant supply system directly upstream of the high-temperature SCR catalyst. The high-temperature SCR catalyst is designed to reduce NOx in exhaust gas that has a temperature above a temperature threshold value and to store SOx in the temperature range below the threshold value. The low-temperature SCR catalyst reduces NOx in the temperature range below the threshold value. In each case, the exhaust gas flows through the high-temperature SCR catalyst. An exhaust-gas bypass valve or flow control valve is arranged directly upstream of the low-temperature SCR catalyst. If the temperature of the exhaust gas is greater than or equal to the temperature threshold value, the exhaust gas is completely conducted past the low-temperature SCR catalyst. The high-temperature SCR catalyst advantageously contains a molecular sieve as a catalytically active layer, and the catalytically active layer of the low-temperature SCR catalyst is preferably a manganese-containing mixed oxide.

When it is determined that control of warm-up of a catalyst is necessary at the time of start of an engine, an ECU starts warm-up control. Initially, the ECU performs first processing for a first set time period. In the first processing, the ECU sets the engine to an idle state and fully opens a waste gate valve. When the first set time period has elapsed since the first processing was started, the ECU performs second processing. In the second processing, the ECU sets the engine to a prescribed rotation speed and fully closes the waste gate valve. When a second set time period has elapsed since the second processing was started, the ECU quits the second processing and quits warm-up control.

Methods and systems are provided for diagnosing an active exhaust valve in an exhaust system based on thermal data. In one example, a method may include indicating degradation of a first active exhaust valve positioned in a first exhaust pipe of a first engine bank based on a difference between a first temperature of exhaust downstream of the first active exhaust valve and a second temperature of exhaust downstream of a second active exhaust valve positioned in a second exhaust pipe of a second engine bank. Degradation of the valve may be confirmed based on thermal image data acquired at outlets of the first and second exhaust pipes.

Methods and systems are provided for on-board diagnostics of components of an exhaust gas heat recovery (EGHR) system including engine coolant temperature sensors coupled to the system. Degradation of one or more of a first coolant temperature sensor coupled upstream of a heat exchanger of the EGHR system and a second coolant temperature sensor coupled downstream of the heat exchanger may be indicated based on a difference between a modeled coolant temperature and a measured coolant temperature, the modeled coolant temperature based on one or more of heat transfer between a heater core and vehicle cabin, and heat transfer between exhaust flowing via the heat exchanger and coolant flowing through the heat exchanger.