P0171 and P0174 troubles

[ejkob]

I have read many blogs on this subject and maybe someone here can help. I have a 2000 explorer with a 4.0 SOHC engine with 174000 miles on it. In the last year I have had a new computer, new MAF, new O2 Sensors, new head gaskets and the idle control replaced. (Cannot remember the name). I still cannot get ride of the lean codes. They only seem to trigger at a stop sign and when the engin is warm. These are the only codes that ever show up! The fuel pressure tests OK! At a stop, the engine seems to run rough as the RPM's fluctuate between 900 to 500 as if the motor is starved for air or fuel, or feels like there is a vaccum leak. There is NO vaccum leak as I have check this over and over. When I just come to a stop, the motor will rest at about 900RPM and then suddenly start hunting. Now I have been told the fuel pump may be the problem since fuel is regulated by the computer. Is it possible my fule pump is crazy? By the way, my fuel mileage is down to 14 mph!!! HELP

Thanks

 

[jasdoz]

P0171 and P0174 codes

Had the same codes on my 2000 explorer. Got rid of mine by cleaning
the computer ground. Bonded using aircraft type bonding brush.

 

[cjp_xsport]

Likewise, had the same codes consistently showing up on my 2002 Sport (111,000 miles). Swapped out the DPFE (didn't fix it). Found a vacuum leak at the hose elbow of the plastic rail which runs along the passenger side of the intake as the line entered the front of the intake manifold just below the throttle body. Changed the entire plastic rail and have not seen codes for a week. Used to get the codes after every third start.