EGR Valve Position (EVP) Sensor
WARNING: This page is about a different car, the 1995 Ford RV Cutaway, 1995 Ford Econoline, 1995 Ford Cutaway, and 1995 Ford Club Wagon. However, it is still accessible from the selected car via links, so may be relevant.
EVP sensor is attached to the EGR valve assembly and indicates position of EGR valve to the PCM. Valve is located on top of EGR valve.