"Cat" is short for the catalytic converter. Part of the emissions system installed inline in the exhaust under your van.
"Coil 3 driver on the computer". The Powertrain Control Module (PCM/computer) supplies a constant voltage to the coil pack while the engine is running. It also contains a voltage driver circuit for each of the three coils in the coil pack that turns the ground on and off to the individual coils.
Last edited by Cougar41; 06-17-2011 at 12:34 AM.