Questions and Answers

Engine Code Won't Go Away

Q. I have a 1995 Mercury Mystique LS (automatic), V6, 2.5 DOHC about 75,000 miles and the engine light is coming on. I had it checked and the diagnostic said that the EGR and Pressure Valve needed to be replaced. I had this done and the engine light still comes on. I have had it back to the shop and they said they can't find why the engine light still comes on. It actually stayed on for my 45 minute commute to work yesterday. And I noticed when I got to work that the hood of my car stayed cold after the 45 minute commute. Does this sound normal? Do you know why the light would still come on?

Thanks,
CK

A. I have seen so many people get burned with diagnostic codes. If you are getting a code P0400 through P0408, the computer is saying there is a problem in the system, not necessarily the EGR or pressure valve itself. With the replacement of both valves, that just about confirms the fault is in the wiring or possibly a restricted or clogged EGR tube or manifold passage.