Differential Pressure Feedback Electronic (DPFE) Sensor
WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford Econoline, 1995 Ford Club Wagon, and 1995 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Faults in DPFE sensor or circuit should set a Diagnostic Trouble Code (DTC). See QUICK TEST in the appropriate TESTS W/CODES - EEC-IV (4.9L) article. If no DTC has been set, see CIRCUIT TEST DL in TESTS W/CODES - EEC-IV (4.9L) article.