04 F150 w/ 5.4L V8 w/ just over 56K on the odo.

A few months ago, it developed a bad miss. I checked the plugs (new in December), new fuel filter in December, checked/cleaned the air filter, pulled the MAS and cleaned it, pulled the throttle body and cleaned it. It seemed to be running fine after that.

Lately, it's been missing a little bit again. At idle I notice the miss every so often at random. I could be sitting at a stop light and feel the miss once. Sometimes I don't feel the miss sitting at a stop light. It's very random. I also noticed lately that while I'm cruising the highway at 65 - 70 and slightly ease off the accelerator, the truck bucks pretty bad. It's not throwing any codes.

I took it to the dealership this morning. They ran the diagnostics and said that the COPS on cylinders 3 & 7 are bad. I bought 2 COPS there at the dealership and put them in as soon as I got home.

I drove in to work and the truck still has the same symptoms. What now? I'm at a loss.

The dealership said that the PCM has to be reflashed when you change the COPS. I know that is BS and I told them so.

The only thing I didn't do when I changed the COPS was pull the battery cable. I will do that tonight, but doubt it will change anything. Besides, which cable do you disconnect and for how long?

 

3 and 7 are the 3rd coils back on each bank. with that said did you replace the correct coils? just need to check because there has been cases of the wrong coils being replaced. what brand plugs did you use? pulling the battery cable will clear the codes but if its still clearly misfiring then the problem isnt fixed.

 

Yes, I replaced the correct ones. When the plugs were replaced, I bought the one-piece plugs that everyone is replacing the two-piece plugs with. I believe they were Bosch. There are no codes. I just wasn't sure if pulling the battery cable will allow the PCM to reset or something.

 

The only one piece plugs for the 3v are Champions - and people have been having mixed results with them. I'd pull them and look at them.

 

You mean you changed your plugs with the battery connected ? Why ? That's a very bad idea. First thing you do is disconnect the battery , so you don't fry the PCM and/or hurt yourself .

Champion Plugs. Good Luck with those, -there complete crap in these Fords, - I don't care what anybody says, - I've heard enough bad about them to determine that conclusion.

BTW- I think what service was trying to tell you is that your vehicle will reboot after a plug change. IF you followed procedure. But hell, you didn't disconnect the battery, - so there's no tellin what the problem may be now. Could be the PCM and coil driver. I know the plugs are one. - Just sayin.