i seem to have wasted 200$$ for a superchip for my 91 seville. when i turn the key, i get the PASS theft deterent and the "wait 3 minutues" thing. thing is, the car will start after that, but then runs like pure shit. i have matched the serial numbers for the ecm with the old one i had to replace some time ago, and they do indeed match, but i just wonder why the car runs so poorly with the chip. if anyone has any suggestions for this problem, let me know. thanks, illuminaP.

BTW, when i first placed the order for the chip, i gave them the code for my old ecm, which they said they could'nt emulate. when i gave them the current ecm code, they could work with that one.