The Mass Air Flow (maf) sensor measures the amount of air which passes through it. The ecm uses this information to determine the operating condition of the engine, to control fuel delivery. A large quantity of air indicates acceleration, while a small quantity indicates deceleration or idle.
This sensor produces a frequency output between 32 and 150 hertz. A scan tool will display air flow in terms of grams of air per second (gm/sec), with a range from 3gm/sec to 150 gm/sec.