After a long discussion with my mechanic we ended up pulling the front cover off again and found one of the new cam phasers that was 6 months old was bad. The hole of the pin that locks it in place was oblonged causeing the timing to jump all around. That is why bank one cylinder contrabuitons was all over the board at idle. hope that helps

mtbinva what all have you done to yours and what is it doing?

OK, lots of research and lots of suggestions, so I want to type up the synopsis of what has happened so I can narrow down my search to fix the issue. I’m unemployed, so money becomes a bit of and issue as well.

2005 F150 FX4 SC

Issue began with a low RPM harsh stutter. Codes said Cylinder 3 misfire and running too lean. Last December I had the plugs changed, 2 days after Christmas. Truck ran great for two weeks, and then the check engine light came back on; multiple misfires and running too rich, bank one and two running to lean. Only happened when it was cold, but would then run fine. There was the faint spell of gas.

Again, the rough idle was only when cold. Two weeks ago, while driving, the engine started to run so rough; it could hardly make it up a small grade. I replaced the O2 sensors since the truck has a lot of mile on it. Very marginal improvement but goes back to a rough idle. It almost gives the sense of the timing being way off.

No codes showed up as of yet. I’ve had many opinions on the issue, and all “sound” plausible.

My first thought is to change the coil packs. It seems the misfires are so bad it can hardly run. Second thought was since there was the cold rough idling and then gas smell is the Cat’s are fried due to a fuel dump into them. The dealer said there might be an issue with the Cat’s. Again, this is simple speculation at this point.

Any suggestions are GREATLY appreciated. I do have the OBDII reader, and two apps on the iPad that lets me read the codes, and one simple app that lets me add and read PID’s. Any suggestions on where to start and get the performance of what the OBDII gives me would be awesome.

Again, I appreciate any assistance.

I started the truck today, and this is what I was able to get.

I started the truck and ran the computer. No codes yet, and the truck barely idles.

Pending code: P0353 Ignition Coil "C" Primary/Secondary circuit (per DashCommand)

Code verified with EngineLink HD.

Per Ford codes: P0353 Ignition coil no. 3 primary circuit fault


This error did exist prior to the plug change. I know the stored codes before I reset the computer was multiple misfire, all cylinders and too lean a condition banks one and two. Sadly I do not have those codes since it was read at an auto-parts store and I've since reset the computer.

Truck started and idled rough, barely ran. Backfires, up front, the cat I believe but not verified.

since you are having problems with both banks have you cleaned your mass airflow sensor?

I did BEFORE the plug change. no change. Thats not to say its bad now.

Could the FDPM be at issue?

im not really sure. normally the fdpm goes bad it will not start

yours really sounds like a plugged cats..any way to pressure check infront of and behind the cat witha pressure gauge?

No, I have not as of yet.

I replaced the #3 COP; however it will not start. Cranks smoother, but no start. I have to get a regular 5/8" since the one I have has a swivel on the end. I believe the plug is loose and will test check in the AM. The old COP smelled of gas.

Pull the front o2 sensors ands let them dangle we can worry about the coil primary circuit later as that will not cause a no start nor a rough enough idle to die out once o2 are pulled start truck and see how it idles.