I have a 04 F150 heritage that is a problem child

manicmechanic007

5 Year Member
Sep 26, 2017
2,275
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Roy, Utah
Sorry, very long intro
04 150 heritage 4.2 4x2 5 speed
Fails I/M, Check engine lamp on, codes P0303 P0316 one fuel trim + .24 the other .07negative
I cannot remember exactly which fuel trim was which number. The truck defiantly runs on 5 cylinders
I have replaced the intake gaskets both uppers and the lower
I have replaced all 6 injectors with ford ones
New Motorcraft ignition coil
I have had the intake off numerous times, enough that I have changed the isolator bolts twice i think
I have not smoke checked it because I have no smoke machine
It does have intermittent lean codes on both banks
The Maf has been replaced with aftermarket one and a new Motorcraft one
I have tried a couple of different throttle air bypasss valves
I have a New PCV valve and Hose to the valve cover
The EVAP hose is intact and the valve does not leak
Absolutely lost on this pile, ready for a grenade
Any help appreciated
 
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I had an 02’ 4.2-that threw lean codes for awhile-i replaced the intake gasket as well as the plenum gaskets and the imrc rod ends etc. after breaking down and buying a cheap Walmart smoke machine and some fuel line-i found the plenum to be very lightly leaking through out the housing of the upper plenum. Dunno if you’re having the same issue or not- but with Halloween coming- Walmart will have those cheapy smoke machines out lol.
 
Maybe that is how I will finally get me one of them
Did get the SOB fixed with the intake bolts and one injector (for now anyway)
I can pass I/M now and get license plates
Take the dog grouse hunting
How / where did you feed the smoke into the intake