Mod Chip

[89RI]

Hi - the previous owner of my 89' said that the car had a mod chip. Where would I find this "chip"? And how do I know if its factory or aftermarket?

 

[TedC]

Welcome to CAC...

EPROM is housed inside the ECM.

Depends... One could reprogram the stock EPROM, overwritting what shipped from GM. One could program a new EPROM, replacing the stock EPROM. One could add a "daughter" card to the stock EPROM that modifies some of the default settings. You would need to pull the ECM and the EPROM, then use special hardware/software to download EPROM data and compare to stock settings.