Hey guys,
I've read up on many posts about this popular problem but I'm running out of patience and money trying to fix this problem. The details...
2002 supercrew 4wd 5.4 Lean codes both banks. I did a smoke test and found defective vacuum line, repaired that. Codes came back. Replaced fuel filter, DPFE, EGR valve, PCV and hose going to back of manifold, up stream o2 sensors and MAF sensor.
I have a cheap code reader but it gives a freeze frame info, I assume at time code is triggered. Long term fuel trim1@21.1% Long team fuel trim2 @ 24.2%
Short term1 @ 11.7% Short term 2 @ 10.9% Sometimes I can drive 150 miles before they come back or 30 miles? Driving me to drink!
If anyone can offer help it would be much appreciated, thanks!

 

intake manifold leak ? don't know if you smoked it or not.

 

You might look at your fuel pressure regulator. Can give too much or not enough. Causing your lean code