How does the air flow when the electronically controlled engine is idling? From air filtration to where?

1, gasoline vehicle: 1) Engine air using idle valve is composed of air filter, intake hose, air passage beside idle valve, behind throttle, intake manifold and cylinder; 2) Idle air intake of vehicles using direct-acting throttle or electronic throttle is to directly open the throttle at a certain angle to let air in, not the idle valve.

2. Diesel vehicle: There is no throttle, and air directly enters the intake pipe from the air cleaner and then enters the engine.

3. If it is combusted in the cylinder, it will be directly discharged along the exhaust manifold through the exhaust valve and pass through the main pipe, three-way catalytic converter and muffler.