nmbowhunter06

I have an 04 f150 with a 5.4 triton 3v. About 2 weeks ago I got a check engine light with a p0302 code for cylinder #2 and p0352 twice on the truck. The truck only misfired when tge truck shifted into overdrive going down the freeway. Sitting at idle no misfire or driving around town Took it into a shop where they said it was injector and replaced it with an OEM injector but it didn't fix the problems.they also said it was a vacuum leak and took my intake off to get to it. I pulled the truck out of that shop anD drove down the road and now the truck misfires at any speed above 45mph and has no power...you try to accelerate and the motor revs up but accelerates very very slow.took it to another shop where they ran vacuum leak tests and tests on the wiring and all checks out ok ....they swapped my injectors,plugs and coil packs around and it stayed in #2 cylinder.they gave the diagnosis that it is burnt valves or cracked piston but they never removed my head just took off my oil fill cap and saw some smoke. Quoted me a new engine. So i m gonna take it to the dealership Monday. I think it has to do with the electrical or ecm . Additional details plugs were done in august and only have 5,000 miles on them. A month after I got plugs done I had 2 misfires and the problem was two bad plugs. All this started happening after plugs were changed.please any help I'm at my wits end

cccougar2

My 04' 5.4 triton seems to just "rev" as I'm driving along. Almost like it is neutral and I hit the gas except while I'm driving. It did have a jerk or shudder with a lag or lack of power when I accelerated slightly and when it did that I would just give it a little more gas to get it "through" the sluggishness. Now it does the rev thing but only with overdrive on. As soon as I turn the overdrive off then she drives just fine. Came here looking for answers myself. I'm thinking I'm going to search more on overdrive issues. Hope this makes sense. If you have the same issue, let me know what you find out.

Tailrace

iTrader: (1)

A buddy of mine has an F250 with the 5.4 and he had the same exact thing happen just recently. He had the plugs changed about 6 months ago, so we kinda ruled that out. I helped him clean the MAF and the throttle body, replaced the missing foam on the bottom of the air cleaner box, and were ready to swap the cop's out. But first he brought it to a shop and they tested the cats.....bingo! $700 for the parts and $125 labor and the truck runs like brand new! Did you have your cats checked....just an idea?

techrep

iTrader: (1)

You stated they swapped things around....did they swap plugs also...check your FPDM and the condition of your cat's

nmbowhunter06

Well got it running "alright" cylinder #2 misfire just went away on its own kinda weird. #6 started to show up so the shop pulled the plug and it had detonated the plug. I put a brand new plug and injector and now the truck only misfires at idle when its first started up in the morning and once you start driving no misfire. Swapped coil from #5 to #6 and still idles rough. I had the cats checked at an exhaust shop and they said the cats are good. Its not as sluggish but its still there. I keep getting a code for the intake manifold runner control so I'm goona look more into that code is p2006. The shop took my intake manifold off and now its throw that code so I think they messed up that runner control.

techrep

iTrader: (1)

Your still far from needing a new motor huh ??

sglover

I would look back there at the IMRC and make sure any wiring or vacums are all on, sounds like they may be your problem. If I pulthe intake I am replacing any of those components I can. The clips that hold the rods get old and break up. Good Luck!