My buddy has an EF DPFI to MPFI conversion using OBD0. I have chipped a PR4 and loaded a stock ROM and the car runs fine. I tried to use Turboedit to modify the stock PR4 ROM and disable the O2. After burning using the exact same process all I get is solid CEL. I re-burned the chip with the stock PR4 program again and everything is fine. What am I doing wrong?

 

Maybe you had put the chipped backwards on the ecu. It sounds like you have no more issue after that.

 

Nah, that's not it. Double and triple-checked. Works when burning stock map. Doesn't work when burning map with disabled O2.