An air intake system offers a larger and straighter airflow path into the engine of the vehicle. It usually consists of three main parts: air filter, mass flow sensor, and throttle body. Some intake systems can be highly complex, and often include specially-designed intake manifolds to optimally distribute air and air/fuel mixture to each cylinder. Aftermarket air intakes are offered in many different designs and sizes, but all of them are designed to have as little air flow restrictions as possible.

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