EGR PFE Sensor - Diagnosis

89ford06

EEC IV - 1.9L, 2.3L HSC & HSO, 2.9L, 3.0L AND 3.8L - PFE SENSORS - DIAGNOSIS FOR REPLACEMENT

Article No. 89-9-9

FORD: 1988-89 ESCORT, TAURUS, TEMPO

LINCOLN-MERCURY: 1988-89 CONTINENTAL, SABLE, TOPAZ
LIGHT TRUCK: 1986-87 RANGER

ISSUE: The pressure feedback sensor (PFE) in the exhaust gas recirculation system (EGR) is sometimes replaced unnecessarily. The exhaust system should be thoroughly checked for restrictions before the pressure feedback sensor is replaced.

ACTION: Refer to the EEC-IV Pinpoint Tests in the Engine/Emissions Diagnosis Manual, Volume H and the following diagnosis procedure to determine if the pressure feedback sensor should be replaced.

1. Perform the "Key On Engine Running" (KOER) self-test to check for higher than normal exhaust backpressure. If service codes "34" or "35" are present, higher than normal exhaust backpressure could be present.

NOTE: DO NOT REPLACE THE "PFE" SENSOR AT THIS TIME.

2. Check the entire exhaust system for possible restriction. Backpressure is an indication of a restricted exhaust system, possibly a plugged catalytic converter.

3. If the exhaust system is restricted, repair as required. Do not replace the "PFE" sensor. If the exhaust system is not restricted, continue with normal diagnostics as outlined in the Engine/Emissions Diagnosis Manual, Volume H.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 680000