Differential Press. Feedback Elect. (DPFE) EGR Transducer
WARNING: This page is about a different car, the 1994 Mercury Grand Marquis, 1994 Lincoln Town Car, 1994 Lincoln Mark VIII, and 1994 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
Faults in DPFE transducer or circuit should set a service code. See QUICK TEST in TESTS W/CODES - EEC-IV (4.6L) article in the ENGINE PERFORMANCE section. If service code has not been set, see CIRCUIT TEST DL in TESTS W/CODES - EEC-IV (4.6L) article in the ENGINE PERFORMANCE section for diagnostic procedures.