Exhaust BACKPRESSURE EGR System: Notes

Two types of backpressure EGR valves are used, a positive or negative backpressure valve. These valves may be identified by the letter in the last position of part number. Letter "P" designates a positive backpressure valve and letter "N" a negative backpressure valve.

Some 5.0L and 5.7L V8 models have backpressure EGR valves with a temperature sensor built into valve base. On these models, ECM monitors EGR valve base temperature. If EGR valve does not open, base temperature will be cool. Temperature sensor will then signal ECM to turn on "SERVICE ENGINE SOON" (SES) light.