OK, here is my quandary. My 2001 ff zx3 has a check engine light, advance auto tells me it is the app sensor, Not trusting them completely, I look at my pedal and sure enough, there is a sensor to the right of the pedal. I am confused due to the fact my car still has a throttle cable, a mechanical link, no drive by wire, so why is this sensor there? What does it do? I absolutely get the drive by wire set up, but don't know why my car has this sensor. Any knowledge or educated guesses welcome, thanks