In an exhaust gas processing device, an air-fuel ratio sensor is provided such that a measuring portion is located in a region surrounded by a downstream-side end surface of a TWC, an upstream-side end surface of a GPF, and an inner wall surface of a case against which the exhaust gas G that has passed through the TWC flows, that is the region a region on the GPF side of the center of the TWC.

A side vehicle body structure ensures rigidity and shock absorption performance of the body, avoids widening of the body, and smooths the flow of exhaust gas. Embodiments include an engine, an exhaust apparatus, and a rear pillar extending upward from a rear-side portion of a side sill extending in the vehicle front-rear direction. The exhaust apparatus is disposed along the vehicle front-rear direction on the vehicle-width-direction outer side relative to the side sill. An exhaust system member is located at a going-around portion, with respect to the rear pillar, from the front side to the rear side and from the outer side to the inner side in the vehicle width direction. The rear pillar has a cross section orthogonal to the vehicle up-down direction having a shape in which a portion between front and rear ends is located on the vehicle-width-direction outer side relative to these front and rear ends.

An exhaust gas cleaning system includes a particle filter device comprising a casing, plural hollow ceramic filter rods arranged at least partly inside a gas passage of the casing, and a gas inlet and gas outlet. The particle filter device guides exhaust gas from the gas inlet, through the gas passage and to the gas outlet. The particle filter device further comprises a perforated plate extending at least partly along the filter rods and partly blocking an exhaust gas flow path from the gas inlet to the gas passage. The perforated plate defines openings allowing exhaust gas to flow into the gas passage. The filter rods are gas permeable to allow exhaust gas to penetrate, during filtration, a respective wall of the filter rods and flow into the filter rods. A respective open upper end of the filter rods communicates with the gas outlet so exhaust gas leaves the casing.

An exhaust system for an engine has a volume element such as a muffler or a silencer. First and second exhaust pipes are connected as dual exhaust pipes upstream of or downstream of the volume element. The first exhaust pipe has a first length (L1). A valve is positioned in the second exhaust pipe at a distance (D) from the volume element. The distance D is a fraction of L1 such that the second pipe is a resonator for the first pipe with the valve in a closed position. A method of controlling exhaust noise includes positioning a valve in the first exhaust pipe at a distance (D) from a volume element with D being a specified fraction of a length of the second exhaust pipe, and closing the valve such that the first pipe provides a resonator for the second pipe to counteract standing wave in the second pipe.

An exhaust system for an engine has a volume element such as a muffler or a silencer. First and second exhaust pipes are connected as dual exhaust pipes upstream of or downstream of the volume element. The first exhaust pipe has a first length (L1). A valve is positioned in the second exhaust pipe at a distance (D) from the volume element. The distance D is a fraction of L1 such that the second pipe is a resonator for the first pipe with the valve in a closed position. A method of controlling exhaust noise includes positioning a valve in the first exhaust pipe at a distance (D) from a volume element with D being a specified fraction of a length of the second exhaust pipe, and closing the valve such that the first pipe provides a resonator for the second pipe to counteract standing wave in the second pipe.

A vehicle, such as a straddle-type vehicle, can include an engine, a catalyst and an air cleaner. The catalyst can be disposed in an expansion chamber of the vehicle. At least a part of the air cleaner can be disposed above a swing arm of the vehicle, and at least a part of the expansion chamber can be disposed below the swing arm. The air cleaner can further be disposed to the rear of a shock absorber of the vehicle. Thus, the influence of heat from the catalyst and the engine on the air cleaner can be reduced. Consequently, efficiency of air induction into the engine can be increased, thereby improving engine output.

A vehicle, such as a straddle-type vehicle, can include an engine, a catalyst and an air cleaner. The catalyst can be disposed in an expansion chamber of the vehicle. At least a part of the air cleaner can be disposed above a swing arm of the vehicle, and at least a part of the expansion chamber can be disposed below the swing arm. The air cleaner can further be disposed to the rear of a shock absorber of the vehicle. Thus, the influence of heat from the catalyst and the engine on the air cleaner can be reduced. Consequently, efficiency of air induction into the engine can be increased, thereby improving engine output.

A device and a method for reducing carbon monoxide, hydrocarbons, nitrogen oxides and soot particles present in the exhaust gases of diesel engines are provided. The device includes 1) a diesel oxidation catalyst for the oxidation of carbon monoxide, hydrocarbons and nitrogen monoxide; 2) a first unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; 3) a catalytically activated particulate filter, containing a wall-flow filter substrate comprising a catalytically active material that promotes the selective catalytic reduction of nitrogen oxides to form nitrogen; 4) a second unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; as well as 5) a catalyst for the selective catalytic reduction of nitrogen oxides to form nitrogen.

A device and a method for reducing carbon monoxide, hydrocarbons, nitrogen oxides and soot particles present in the exhaust gases of diesel engines are provided. The device includes 1) a diesel oxidation catalyst for the oxidation of carbon monoxide, hydrocarbons and nitrogen monoxide; 2) a first unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; 3) a catalytically activated particulate filter, containing a wall-flow filter substrate comprising a catalytically active material that promotes the selective catalytic reduction of nitrogen oxides to form nitrogen; 4) a second unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; as well as 5) a catalyst for the selective catalytic reduction of nitrogen oxides to form nitrogen.

Provided acoustic devices include an external housing defining an expansion chamber and a wall extending through and partitioning the expansion chamber into a central chamber and a peripheral chamber adjacent the central chamber, wherein an inlet and outlet communicate with the central chamber, and wherein the wall includes a plurality of apertures formed therethrough to allow air movement to and from the central and expansion chambers, the plurality of apertures sized to provide an average flow resistance ranging from 100 MKS Rayls to 5000 MKS Rayls. The acoustic devices advantageously show significant sound attenuation while streamlining air flow to reduce pressure drop across the expansion chamber.