When 98 Deville is cold it runs fine....but when it warms up, as it shifts into high gear it loses power and just seems to just stutter. It is also using gas like there is no tomorrow. Anyone have and idea what the heck is going on? Thanks
First off, run the codes to see if there are any DTC's stored. Then check the FPR. "using gas like there is no tomorrow" is a big clue and the FPR will not set a DTC. If you don't know how to check it, go to the Tech Tips section. It is quite easy. Post your results.