Methods and systems are provided for an exhaust muffler system with multiple inlets of different diameters. In one example, the muffler system may include multiple sets of inlet pipes to a muffler with each set of inlet pipes including pipes of different diameters with valves controlling exhaust flow into the inlet pipes. Exhaust from an engine bank may flow to a distinct set of inlet pipes and a distinct outlet pipe of the muffler via a separate exhaust passage.

An exhaust system provided to an engine having an output shaft extending in a specific direction, includes an exhaust passage, a turbocharger having a turbine housing, and purifying parts. The exhaust passage includes a first passage part extending to one side in the specific direction from the turbine housing, a third passage part extending in the specific direction below the turbine housing, and a second passage part extending upward from one end part of the third passage part in the specific direction. A center axis of the second passage part inclines so that an upper end thereof is located on one side of a lower end in the specific direction. The first passage part has in an upper surface thereof an inclined part to which one of a sensor configured to detect a property of exhaust gas and an injector configured to inject fluid into exhaust gas, is attached.

An exhaust system is provided to an engine having an output shaft extending in a vehicle front-and-rear direction. The system includes an exhaust passage including a first passage part extending forward from a turbine housing of a turbocharger, a fourth passage part extending in the front-and-rear direction below the turbine housing, a second passage part disposed so that it extends vertically and its center axis inclines forward and upward, and a third passage part having a downstream connecting part extending forward from a front end of the fourth passage part, and an upstream connecting part extending forward and upward from an upper part of a front end of the downstream connecting part. The downstream part has, at a lower part of its front end, an attaching part extending downwardly from a lower edge of the upstream part, and to which a sensor or an injector is attached.

The invention relates to an exhaust gas aftertreatment system for an internal combustion engine (10), in particular for an internal combustion engine (10) which is charged by means of a turbocharger (30) and spark-ignited by means of spark plugs (16). A particulate filter (24) and an electrically heatable three-way catalytic converter (26) downstream of the particulate filter (24) are arranged in a position close to the engine in an exhaust gas system (20) connected to an outlet (12) of the internal combustion engine (10). A further three-way catalytic converter (28) is arranged in the underbody position of the motor vehicle downstream of the electrically heatable catalytic converter (26). According to the invention, the electrically heatable three-way catalytic converter (26) is heated electrically after engine start, and the particulate filter (24), the electrically heatable three-way catalytic converter (26) and the further three-way catalytic converter are additionally heated by the exhaust gas flow from the internal combustion engine (10). The electric heating of the electrically heatable three-way catalytic converter (26) is switched off when the electrically heatable three-way catalytic converter (26) has reached its light-off temperature.

An engine cover capable of appropriately covering the upper side of an engine is provided. An engine cover is provided with a plate member installed above an engine, and the plate member is provided with a reinforcement structure for increasing the torsional rigidity of the plate member.

A vehicle exhaust system includes a first component that receives exhaust gas output from an engine and a second component that is fluidly coupled to the first component to define an upstream portion of a vehicle exhaust system. A vehicle frame member includes an internal acoustic volume. A pipe connects the internal acoustic volume in parallel to the upstream portion of the vehicle exhaust system.

A saddle riding vehicle includes a body frame, an exhaust pipe, a muffler, and a catalyst. The body frame includes a main frame, a seat frame that extends rearward from the main frame and supports a seat for occupant, and a rear frame that extends from the main frame upward to a rear and is connected to the seat frame. The exhaust pipe extends rearward of the vehicle from an exhaust port of an engine. The muffler is connected to a rear end portion of the exhaust pipe. The catalyst is disposed in the muffler. An air cleaner box is disposed rearward of the engine. The catalyst disposed in the muffler is disposed in a space surrounded by the main frame, the seat frame, and the rear frame and overlaps with the air cleaner box as viewed in a side view of the vehicle.

A work vehicle includes an engine, a particulate filter, and an oil separator. The particulate filter is connected to the engine to collect particulate matters contained in exhaust gas from the engine. The particulate filter is provided to overlap with the engine when viewed in a height direction along a height of the work vehicle. The oil separator is connected to the engine via a blow-by-gas discharge pipe to catch a liquid component in blow-by-gas from the engine. The oil separator is provided between the engine and the particulate filter to overlap with the particulate filter when viewed in the height direction.

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.

An engine (1) includes: an exhaust purification system (70) housing a GPF device (73) for purifying exhaust gas; and an EGR passage (52) connected to a portion of the exhaust purification system located downstream of the GPF device, and the engine is mounted in an engine compartment (R) defined in a front portion of a vehicle body. The exhaust purification system is located forward of a dash panel (103) constituting the engine compartment, and is positioned to extend toward a tunnel portion (T) of the dash panel. An upstream end portion (52c) of the EGR passage is connected to a lower portion of the exhaust purification system in a vertical direction of the vehicle.