Summary The primary components of the automotive intake system are: Intake manifold The intake manifold is attached to the cylinder head. Its construction and design depends on its application. It is normally made of an aluminum alloy. On carbureted engines, the intake manifold supports or houses the carburetor. While on EFI engines it can house or support a throttle body. Throttle body/carburetor Throttle body The intake manifold can accommodate a carburetor or a Throttle Body Injection unit as illustrated. In either case the mixing of the air/fuel mixture is done at the manifold base. The butterfly shaft connected to the throttle cable controls the airflow through the unit. Multi-point throttle body In multi-point EFI systems, a throttle body is attached to the intake manifold. While the butterfly shaft is attached the throttle cable, it also has a Throttle Position Sensor (TPS) attached to it as well. The TPS signals the ECU of the throttle opening position so it can complete its fuel requirement calculations. Air induction components The air induction components consist of an air cleaner and housing, solid and flexible-duct tubing, and connectors. The air induction system draws in ambient air from the environment. The inlet opening may be located in various positions under the hood. Air cleaner The air cleaner filters the incoming air. The air cleaner element may be manufactured from pleated paper, oil impregnated cloth or felt, or in an oil bath configuration. Another function of the air cleaner is to muffle the resonation (that is, dampen the noise) of the swirling incoming air. The location of the air cleaner is dependent on the available space and the hood design Ducting The ducting can be made of hardened plastic with flexible rubber couplings to absorb engine movement. These are usually secured in place by metal worm drive clamps.