For 1990-2009 cars

The air induction system draws outside air into the combustion chamber. The intake air flows through a forward mounted duct and into the air cleaner assembly. The intake air passes out of the air cleaner assembly, through the mass air flow sensor and inlet duct, to the throttle body. The throttle body houses a throttle valve that controls the volume of air entering the intake manifold. A metered amount of air also enters the intake manifold through the idle air passage in the idle air control (IAC) valve attached to the throttle body. From the throttle body the intake air flows into the plenum chamber of the intake manifold and is then distributed to each cylinder through an intake manifold runner.

The intake air is mixed with fuel from the fuel injectors at the entrance to the combustion chamber. An air filter element is incorporated into the air cleaner assembly in order to prevent dirt from entering the engine.