An exhaust muffler to be attached to an engine body includes a casing that includes: a rear member facing the engine body and a front member opposing to the rear member while maintaining a gap between the front member and the rear member, the gap forming a path in which exhaust gas discharged from the engine body flows; at least one guiding member that is disposed in the gap of the casing, extends from the rear member to the front member, and has a through-hole into which a fastening member that fastens the casing to the engine body is inserted; and a catalyst holding member that holds a catalyst that purifies the exhaust gas and is accommodated in the gap of the casing while being supported by the at least one guiding member.

An exhaust muffler has an exhaust inlet, an exhaust outlet, as well as a catalytic converter which, in the flow direction, is disposed between the exhaust inlet and the exhaust outlet. The catalytic converter has at least one throughflow body which includes at least one wire body. At least one first component region of the throughflow body is coated with a catalytically functioning coating. The throughflow body moreover has a second component region which in terms of volume has a smaller quantity of catalytically functioning coating than the first component region.

An exhaust after-treatment assembly for an engine system is provided. The exhaust after-treatment assembly includes a housing having an inlet port, an outlet port, a catalyst disposed within a cavity defined by the housing, and a muffler assembly disposed within the cavity downstream of the catalyst. The muffler assembly includes one or more baffle plates disposed longitudinally spaced from one another within the housing to define at least a first resonator chamber and a second resonator chamber. Each of the baffle plates defines an openings aligned to one another about a longitudinal axis of the housing. Further, a resonator tube extends through the openings of the baffle plates and includes an inlet, a perforated portion and one or more outlet ports formed in a wall of the resonator tube. The perforated portion and the outlet ports, respectively in fluid communication with the second resonator chamber and the first resonator chamber.

A low emissions 2-stroke natural gas fueled engine includes at least one cylinder with an exhaust port in communication with a silencer-catalytic converter unit. The unit has first and second volumes in communication with each other. The first volume damps spurious exhaust pressure excursions and removes particulates in the exhaust. The second volume houses an oxidation catalyst for treating exhaust to reduce exhaust emissions. The engine oil has at most 10 ppm zinc content to reduce metal poisons contained in the exhaust prior to contact with the oxidation catalyst. The engine oil preferably has a very low ash content to minimize sulfur combustion components in the exhaust to reduce masking of the oxidation catalyst. The first volume preferably has a pressure relief valve set to relieve at a pressure greater than the maximum normal operating pressure of the engine to avoid excessive pressure excursions of the engine exhaust from damaging the oxidation catalyst.

A straddle-type vehicle (100) includes a frame (20) and an engine (10) mounted on the frame (20), the engine (10) includes a cylinder head (11) positioned toward the rear end of the frame, and located below a saddle seat (80). The cylinder head laces toward the rear end of the frame, which allows the heated cylinder head of the engine and the exhaust pipe connected to the cylinder head to avoid contact with the vehicle the user's legs while riding the vehicle, so the effect of heat emitted from the cylinder head on the rider's experience is reduced.

A straddle-type vehicle (100) includes a frame (20) and an engine (10) mounted on the frame (20), the engine (10) includes a cylinder head (11) positioned toward the rear end of the frame, and located below a saddle seat (80). The cylinder head laces toward the rear end of the frame, which allows the heated cylinder head of the engine and the exhaust pipe connected to the cylinder head to avoid contact with the vehicle the user's legs while riding the vehicle, so the effect of heat emitted from the cylinder head on the rider's experience is reduced.

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 muffler, connected to an engine through an exhaust pipe, includes a shell serving as a muffler body, an inlet pipe configured to introduce exhaust gas from the engine into the shell, an outlet pipe configured to discharge the exhaust gas out of the shell, and a cap configured to be attached to a narrowed portion of the inlet pipe and control the direction in which the exhaust gas flows out. The cap is provided with an opening through which the exhaust gas passes and which regulates the direction in which the exhaust gas flows out.

A device for the aftertreatment of exhaust gases of an internal combustion engine, having at least one catalytic converter, through which exhaust gas can flow, and at least one muffler formed by a closed volume and through which exhaust gas can flow along an inflow section to an outflow section. The catalytic converter is formed by a honeycomb body that has a plurality of flow channels through which exhaust gas can flow. The honeycomb body is accommodated in a casing tube, which surrounds the honeycomb body, and is connected to the casing tube in a materially bonded manner. The catalytic converter is arranged in the interior of the muffler.

An exhaust system of an internal combustion engine of a motor vehicle includes a particulate filter where particles are filterable out from the exhaust gas by the particulate filter. A selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine is flowable for denitrifying the exhaust gas from the internal combustion engine is disposed downstream of the particulate filter. The exhaust gas of the internal combustion engine is heatable by a combustor at a point disposed upstream of the SCR catalytic converter and downstream of the particulate filter where the combustor provides an exhaust gas of the combustor. Particles are filterable out from the exhaust gas of the combustor by a filter element.