Guys...I have a 04 f150 fx4 5.4 3v with 127000 miles on it. I changed my plugs and cop's for the first time at 120k. Motorcraft plugs and global cop's. Truck ran ok for about 4k miles. At the time of the plug change I also cleaned the maf and throttle body. Around 125k give or take ~ the truck started acting up. Missing and throwing codes on my edge - usually 1 to 3 codes - all igniton coil malfunction. Usually a b or h or all three together. So at 126k I bought 8 new cop's - bwd brand - lifetime warranty. I changed everything out and still same thing. Truck is missing and showing same codes. I took it to a friends shop Sunday and its still there. He has changed cop's out as well as changed the plugs. He just called me and said he is about to same point as me. Truck is still throwing codes. In fact now f and g have appeared as well as b still missing. He said he called a friend at a local ford dealer and he said that it could be fuel related - possible injectors- so my friend said that tomorrow he will look at that first thing then go from there. Guys I am lost and really out of ideas or suggestions - anything that you can offer I would greatly appreciate! Thanks - brett

 

What are the codes?

 

P0351 352 358 I believe

 

I haven't heard anything today from the shop.....guess they are just as confused as I am......

 

Shop just called me again....So far they have changed all the plugs and COP's - cleaned MAF and Throttle body again - changed fuel pressure regulator - and fuel filter. Still throwing codes for ignition coil B and G i believe its p0352 and 357. They are now saying that they are afraid it may have to go to dealer for them to diagnose further. They believe the ECM may be bad......I am really hoping its not but we dont know what to try next. Does anyone have any suggestions?

 

I'd inspect the wiring harness for damage,,

 

Will do......anyone else got any ideas also??

 

Here, look here with what's been going on with mine, plenty of good ideas posted.

https://www.f150online.com/forums/v8...ing-again.html

Also check fuel filter, fuel line pressure, and compression.

 

Thank you - I will go thru all the ideas that are listed......gotta keep trying. I really dont think its the computer....at least I am really hoping it isnt.