parkerwa
New Member
Can someone help? I have a 98 expedition 4x4 with 5.4 L engine122K miles on it. I have the check engine on (for about 4-5 months now) and my first step into correctiong problem was to get autozone to hook computer up. they said EGR valve -- I check removed and cleaned seemed ok to me so I put back on and reset light . Light came back on . I talked to a local mechanic and he said 90% sure it was the Differential pressure switch , so I replaced it with on e from Auto zone - reset light and 30 minutes later light back on . I took to Ford place and had it hooked to their computer as I know theirs tells more and the tech said it was saying the Differential Pressure switch for the EGR valve needs changing. Well I replied I just changed it and there is a new one on. He said it must have been bad out of the box. I took it back and exchanged it for another new one and the light is back on...It is not the Diff Press Switch and the computer is saying it is. I checked it with the prociedure in the Haynes manual and it looks like all voltage measurements are close. What next? does something need cleaning ? holes need clearing out?