2002 Screw, 5.4L, 180k, new PCV and new fuel filter. No fuel in the fuel regulator vacuum line, and MAF is clean. The truck starts right up as it did before the codes. MPG is down and acceleration is a bit sluggish. After I cleaned the MAF the codes came back on the 2nd day, when I changed the fuel filter the codes came back 5 or 6 days later. I rented a fuel pressure tester from 2 different AutoZones, neither worked properly as both had a leak at the Ford Schrader connector. Any suggestions?

 

did you check the PCV hose connection at the back of the air intake? It could have come off when you replace the PCV valve or the elbow back there could have a crack in it.

 

Vacuum leak somewhere...like stated above, check or replace vacuum lines.

 

Could be intake manifold gasket leaking, that's what it was on my 4.2

 

you have a manifold tick? If so if it's bad enough it can throw that code.. If you do have that then be prepared.

 

Cracked manifold and bad EGR...