Exhaust systems for a vehicle are provided. In one example, an exhaust system includes a muffler, a first exhaust outlet pipe fluidly coupled to a first outlet of the muffler, a second exhaust outlet pipe fluidly coupled to a second outlet of the muffler, a bypass duct fluidly coupled to a third outlet of the muffler, and a combined X-Y shaped intersection at which the first exhaust outlet pipe, the second exhaust outlet pipe, and the bypass duct are fluidly coupled to each other.

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, a method may include supplying air to an exhaust system at a location downstream of an emissions control device via the first exhaust manifold, the air not having participated in combustion in the engine, the first exhaust manifold in fluidic communication with a first exhaust valve of a cylinder and an intake manifold, the cylinder including a second exhaust valve in fluidic communication with the second exhaust manifold. The method may further include adjusting an amount of fuel injected to the engine in response to output of a first oxygen sensor, the first oxygen sensor positioned in the exhaust system upstream of the emissions control device.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

Provided is an exhaust system for an internal combustion engine comprising: a first exhaust conduit leading from a first exhaust bank of the engine to a first turbocharger turbine inlet arranged downstream of the first exhaust bank in the direction of travel of a first exhaust stream; a second exhaust conduit leading from a second exhaust bank of the engine to a second turbocharger turbine inlet arranged downstream of the second exhaust bank in the direction of travel of a second exhaust stream; an SCR catalyst arranged downstream of the first turbocharger turbine inlet and/or second turbocharger turbine inlet; and a reductant supply system comprising a distributor pipe and a reductant injector. The distributor pipe is configured to fluidly connect the first exhaust conduit to the second exhaust conduit upstream of the first turbocharger turbine inlet and second turbocharger turbine inlet, and the reductant injector is configured to supply a reductant to the distributor pipe.

An exhaust pipe assembly includes: an exhaust cavity; an exhaust port (234) and at least two air inlets (115) communicating with the exhaust cavity, the exhaust port (234) being disposed at an end of the exhaust pipe assembly; and a water inlet (114), a first part of a water inlet cavity (111), a second part of a water inlet cavity, a water counterflow cavity, and a water outlet (311) that are provided in the exhaust pipe assembly. The water inlets (114) are provided in the same number as the air inlets (115). The first part of the water inlet cavity (111) communicates with the first water inlet portion (114). The second part of the water inlet cavity communicates with the second water inlet portion (114). The water counterflow cavity communicates with the end of the second part of the water inlet cavity located at the exhaust port (234) of the exhaust pipe assembly. The water outlet (311) is disposed at a second end of the exhaust pipe assembly. The first part of the water inlet cavity (111) and the water counterflow cavity each communicate with the water outlet (311).

Methods and systems for operating an engine with split lambda modes are provided. At least one example method comprises, while operating an engine in a condition that is within a resonant frequency region for a default split lambda mode, carrying out a rolling split lambda mode. The engine may be operated with only stoichiometric engine cycles in the default split lambda mode, the stoichiometric engine cycles including enleaned and enriched cylinders. Further, the engine may be operated with a plurality of non-stoichiometric engine cycles when carrying out the rolling split lambda mode, the plurality of non-stoichiometric engine cycles including at least one rich engine cycle and at least one lean engine cycle.

A boosted engine is provided, which includes a first turbocharger having a first compressor and a first turbine, a second turbocharger having a second compressor and a second turbine, and first and second exhaust emission control devices. The engine has a first exhaust port which opens at a first timing, and a second exhaust port which is in parallel with the first exhaust port and opens at a second timing later than the first timing. The exhaust passage has a first exhaust passage connected to the first exhaust port and a second exhaust passage connected to the second exhaust port. The first turbine and the first exhaust emission control device are disposed in the first exhaust passage in this order from upstream to downstream, and the second exhaust emission control device and the second turbine are disposed in the second exhaust passage in this order from upstream to downstream.

A pulse exhaust pipe for use with diesel engines an end of the pulse exhaust pipe is in communication with eight cylinders, and another end is in communication with two turbochargers; the pulse exhaust pipe includes three exhaust pipe sections which are separated from each other, each exhaust pipe section discharging to a turbocharger independently, wherein a first exhaust pipe section is in communication with a first and second cylinder, while a second exhaust pipe section is in communication with a third to a sixth cylinder, and a third exhaust pipe section is in communication with a seventh and eighth cylinder. The pulse exhaust pipe may prevent the backward flow of exhaust gas and inlet air back flow, thus increasing inflation efficiency and improving the uniformity of each cylinder. Also provided is a diesel engine installed with said pulse exhaust pipe.

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, an air-fuel control method for the engine system may include flowing air from the intake manifold through a plurality of engine cylinders to a junction of the exhaust passage and a bypass passage in response to a condition, the junction positioned along the exhaust passage between first and second emission control devices. The method may further include flowing exhaust gas to the first emission control device while flowing the air to the junction.

An outlet manifold is provided and includes an outlet portion having first and second sides and an inlet portion to which the outlet portion is fluidly coupled. The inlet portion has first and second sides corresponding to the first and second sides of the outlet portion. Each of the first and second sides of the inlet portion includes one or more tubular members connectable with corresponding tube joints and a mixing chamber fluidly interposed between each of the one or more tubular members and the outlet portion.