Mercury Grand Marquis
Report: EVP Sensor Failure May Cause Drivability/Fuel Economy Issues
Mercury Grand Marquis Problem
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.
Visitor, 1992 Mercury Grand Marquis
Had it in the shop several time for the same EGR valve and light on