Problem Description and Possible Solution
The EGR valve position (EVP) sensor can fail on this vehicle. The EVP sensor measures the EGR valve position and transmits the date to the engine control computer. If it fails, drivability and fuel economy can suffer, the Check Engine Light will commonly illuminate.
Average mileage: 84,438 (14,300–150,000)
11 model years affected: 1990
, more1994, 1995, 1996, 1997, 2000, 2001, 2005
25 people reported this problem
Check Engine light come on only after the engine is hot The codes are 172/176 C for continual. Code reference ( Engine running to lean.) Replaced vacuum lines and sensor at charcoal canister. replace Both Oxygen sensors, replaced sensors on EGR. I can drive for hours and the light will not come on. After I stop the engine for a period of time say within 40 minutes the light will come on. If I drive with the light on for 10 to 15 miles, the light then will go off. If I stop the engine and restart the light goes off. Driving me nuts Can someone make a suggestion. as to what it could be. I have been told, that it could be a leak in the intake manifold. That was taken off and put back on with a new gasket, when I had Valve guide seals put on. The person that put them on is a longtime mechanic and have used him for years. The engine does not change, as far a running is concerned ,it still runs smooth. No miss, no Idle problems, no hesitation, nothing changes ,other than the Check engine light coming on. The Dealer had it for 2 days and could not find anything wrong. The Vacuum level stay`s steady, does not move. What am I looking for. It has to be something with the mixture, or air intake. I just don`t know. HELP