2004 f150 5.4 3v. keep getting a p0171 code. surges big time under a load. Rough Idle.
I have replace the 02 sensor
maf sensor
intake manifold gaskets
fuel filter

checked the vac lines
no exhaust leaks
ran sea foam throught the gas tank

HELP PLEASE

 

Take a look under the back end of your truck around the area of your spare tire...there's a fuel pump module mounted to the frame...what's it look like ???

 

probably sounds weird but it looks like a tube about 12 or so inches long. couple of fuel lines out of it.

 

"Failure mode effects management", CMP crankshaft sensor?