I just got this CEL today. I just replaced all the ignition components. Coil, plugs, plug wires were all replaced along with the fuel filter. I ran some injector cleaner on the next tank of gas, which would be one that I'm currently on, and now I get this light. I'm thinking that the injector got clogged or something. The truck has 190K on it and it has always pinged. I did use the hotter AGSF22FM plugs. I know that I'm going to get the new fine wires this coming week.

So what do you guys think is causing my misfire?

And for those that will ask, I did not have any other codes.

 

What kind of plugs did you install? It's always possible that you got a bad one....If the plug is ok, try swapping plug wires with another cylinder. After all of that, do a compression test on #6.

 

I used the factory replacement plugs, the AGSF22FM's. You have said that they run hot which I think that they do. I've always ran 89 so I think that helps some with the pinging. I may have a bad plug so I'm going to get the fine wires and see if that doesn't fix it first.

 

I went and got a new plug last night and the one that was in there was fouled to no end. I replaced and it is still misfiring. I reset the PCM and got the code after driving for about 15 minutes today. How much does a Ford Dealership usually charge to diagnose a problem.

I'm going to fuel now. I'm thinking an injector.......Bob, what do you think?

 

Anyone have a different view?

 

Don't go to the dealer just yet. You are properly narrowing things down. Keep going.

What did the fouled plug look like? Was it dark, carbonized, wet, etc. (too much fuel)? Or was it burnt to a crisp (lean)?

Regarding fuel delivery, a bad fuel injector can cause misfires and fouled plugs. Probably a good place to focus on, I have to think.

A bad plug wire can contribute to a misfire, too. Trying another wire is easy, you can swap it with another one, or if you have a spare lying around, put it on.

 

Plug was dark as hell. Guess a wire is a good place to start although they are somewhat new so I'm thinking I got a bad set.

 

I would do a compression check on at least the fouled cylinder. If you know an aircraft mechanic, try and borrow a differential pressure tester and do the whole engine. It will tell the tale.

 

Wow, I'm guessing you are thinking that it is a ring.

 

No more misfire. Went away this morning on the way to work. I think I had a clogged injector and the clog finally went through and burned off.