my 2006 f150 with the 5.4 has a misfire at low rpms and under a load only. i took it to the dealer and they performed an injector pressure test and said it was good, however the problem is still there. there is no code present now, when it first started there was a p0302, missfire of the number 2 cylinder. that code never came back after the dealer worked on it. any ideas?

 

Try swapping coils between #2 and another cylinder...see if the miss changes in character or throws a misfire code for another cylinder.

 

id bet money its a coil. not too much to worry about yet. i drove mine to the shop cuz there was no code and by the time i got there a code popped up so i just went to napa read the code myself and put a new coil in at home

 

thanks alot....ill try the coil thing. it gets me from point a to point b now so im not to worried about it.

 

truck is still miss firing and second dealer cant fid problem. everything checks good but it still runs like crap. did the coil swap didnt work and ive been driving iy for 2 months and still no code.

 

Have you replaced the PCV yet? Check all of the hoses for cracks and pin holes. If replacing the PCV, use ONLY Motorcraft and nothing else or expect miss fires. Uncoded miss fires are generally a PCV issue.

 

Where exactly is he PVC valve, drivers side or passenger, I see hoses on both sides, or is it right on the intake manifold on the drivers side, not on the valve cover? Also replaced all my coils about 6 months ago with the accel units, got rid of all my misfire codes, bought off amazon for about $220 for all 8.

 

right hand or passenger side in valve cover

 

well go and check famous fuel pump module it did solve misfire on mine

 

Intake Manifold could be Flooded of Oil Vapor coming from the PCV valve. Ethanol blended fuel burns hotter and it's capable of vaporizing oil.