Final thought, a lot of guys recommend using motorcraft parts on your truck, especially motorcraft spark plugs, and I believe they may have a good point. I have used them on my mercury car and used them on my truck this last time and they seem to do a better job of staying in the head and not working loose. It makes sense because the plugs were designed for the Ford vehicles.

 

The plugs are motorcraft and when looking at the threads on the plug the lower 1/3 is all that threads in as it tightens up. That being said I'm not sure if that is the distance its supposed to be but that's what's going on. I haven't been able to get back at the plug issue because I had honey do list that took priority on my last day off today now I have my weekend shift coming up. Try to get it one of the nights after work.

 

I am having the same issue with a P0303 code. I have checked everything and just replaced the ignition coil. No luck. Gonna check the plug in a few hours to see if it is loose and could be the problem. Just did the pugs about 500 miles ago. Maybe it worked loose??