A method and system for controlling operation of a two-stroke engine having a turbocharger includes the two-stroke engine comprising an electronically controlled exhaust valve. A throttle position sensor generates a throttle position signal corresponding to a position of a throttle plate of a throttle. A boost box is coupled to the two-stroke engine. A boost box pressure sensor is coupled to the boost box and generates a boost box pressure signal corresponding to a pressure within the boost box. A controller is coupled to the boost box pressure signal controlling a position of the electronically controlled exhaust valve in response to the boost box pressure signal and the throttle position signal.

A method for operating an internal combustion engine includes combusting a fuel and air mixture within a combustion chamber of an internal combustion engine, thereby forming an exhaust gas, passing the exhaust gas out of the combustion chamber, performing a startup procedure, the startup procedure including passing the exhaust gas from the combustion chamber to a storage unit, capturing criteria pollutants of the exhaust gas with the storage unit, passing the exhaust gas from the storage unit to an aftertreatment system, heating the aftertreatment system to an activation temperature with the exhaust gas from the storage unit, and subsequent to heating the aftertreatment system to the activation temperature, performing a secondary procedure, the secondary procedure including passing the exhaust gas from the combustion chamber to the aftertreatment system thereby forming a treated exhaust gas, and passing the treated exhaust gas to the storage unit.

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 exhaust gas purifier including a casing, SCR catalysts (comprising a first SCR catalyst and a second SCR catalyst), a first backflow prevention plate, and a second backflow prevention plate. In the casing, at least a part of the catalyst passage and at least a part of the bypass passage are formed. The SCR catalysts are disposed in the catalyst passage and selectively reduce NOx included in an exhaust gas flowing in the catalyst passage. The first backflow prevention plate prevents or reduces a backflow of an exhaust gas from a second exhaust passage to the catalyst passage.

A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.

An exhaust system for a marine outboard engine including an engine having an engine exhaust port. The exhaust system includes a first exhaust port, a second exhaust port vertically higher than the first exhaust port, a first passage for fluidly connecting to the engine exhaust port and fluidly connected to the first exhaust port, a second passage fluidly connected between the first passage and the second exhaust port, a catalytic converter defining at least in part the second passage, a valve operable to at least partially close the first passage to respectively reduce and increase flow of exhaust gas to the first exhaust port and the second exhaust port, a valve actuator operatively connected to the valve, and a controller operatively connected to the valve actuator for controlling a position of the valve based at least in part on a speed and a throttle request of the engine.

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 setting a cam timing correction based on a difference between a first value and a second value of a flow through an exhaust gas recirculation (EGR) passage, the first value determined based on a first parameter set including a cylinder valve overlap area and the second value determined based on a second parameter set not including the cylinder valve overlap area, and operating at least one of an intake cam and an exhaust cam at a corrected timing using the cam timing correction. In this way, the flow through the EGR passage may be adjusted even without active control of a valve coupled in the EGR passage.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation (EGR) to an intake passage via a ported scavenge manifold. In one example, the ported scavenge manifold includes a first scavenge manifold coupled to a plurality of exhaust runners and a second scavenge manifold coupled to the plurality of exhaust runners via ports. The location of the ports on the exhaust runners combined with adjustments to a bypass valve coupled between the first scavenge manifold and an exhaust passage and an EGR valve coupled between the second scavenge manifold and the intake passage enables exhaust gas to be preferentially flowed to the exhaust passage and blowthrough air to be preferentially flowed to the intake passage under select operating conditions.

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.

A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.