1998 IDle Issues

[Jadenjdawg]

Yesterday my 1998 4.0 started idling very rough. Whenver you try to give it gas it dies. This is the second time it has done this in two weeks. It only happend after driving for forty or fifty miles, when the engine is hot. This morning is started it up and drove across town with no issues. Had it scanned at Auto Zone and it lit up like a Christmas Tree. Error codes: P0174 P0420, P1409, and P0171. 97,000 miles, automatic. HELP

 

[holyford86]

p0171 and p0174 are lean codes, p0420 catalyst efficiency low, p1409 points to the egr vacuum regulator, it controls the egr valve operation and it may be bad. If its bad it's probably causing the lean codes and the rough running