Closed
Closed
They are closed during the power stage.
Closed
Both the intake and the exhaust valve are closed.
-intake: exhaust closed, intake open -compression: exhaust closed, intake closed -combustion: exhaust closed, intake closed -exhaust: exhaust open, intake closed
Closed
The engine may backfire excessively. You may also smell a strong exhaust odor in the riding position. In worst cases, it can cause the engine to run lean.
During the power or combustion stage of a piston cycle, both valves are necessarily closed, because the expansion of gases is driving the piston down.
Possible exhaust leak
inboard gas engine exhaust
The EGR (Exhaust Gas Recirculation) valve position sensor monitors the position of the EGR valve, which regulates the flow of exhaust gases back into the engine's intake manifold. By providing real-time feedback to the engine control unit (ECU), the sensor ensures the valve opens and closes at the appropriate times for optimal engine performance and emissions control. If the sensor malfunctions, it can lead to poor engine performance, increased emissions, and potential engine damage.
fire wall side of engine block under the exhaust manifold.