Description And Operation: Description

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Air Flow Sensor (AFS) is measure the mass of intake air entering the engine, and send the signal to Engine Control Module (ECM).
A large amount of intake air represents acceleration or high load conditions while a small amount of intake air represents deceleration or idle.
The ECM uses this information to control the Exhaust Gas Recirculation (EGR) valve and correct the fuel amount.

Courtesy of KIA MOTORS AMERICA, INC.