Air Fuel Controller - AFC 1.2The AFC 1. 2 is a microprocessor based, stand alone air fuel mixture management device for frequency based Mass Air Flow (MAF) sensors. The AFC performs this fuel mixture correction by receiving the MAF sensors frequency signal, digitally recalculating a modified MAF frequency value and passing this modified frequency to the Powertrain Control Module (PCM). The AFC can apply correction values from 1% to 255% in 1% increments. The AFC Version 1. 2