Aftermarket chips let you reprogram certain functions that your stock ECU won't.
eg air fuel ratio, turbo boost, ignition.
They all hook up to your stock ECU via different ways. They store the changed info in the chip and when taken off your car restore your car to its normal settings.
You can also buy replacement ecu's/computers such as the wolf3d. These replace the whole setup in your car and not just plug into what you already have(to the best of my knowledge).
Your basic trip computer will give you things like distance to empty, distance travelled etc. These are normally offered by your manufacturer as an option unlike the aftermarket chips/ecu's which are installed separately.
Thats a pretty basic rundown.
Proud TQE Operator
1999 Black Manual AU XR6HP
Unichip equipped by Autotech Engineering, Granville
Cam install by Crescent Motorsport, Liverpool
Last edited by loxxr6; 09-21-2004 at 20:11.
Reason: more text added