I have a 97 F150 4.2L V6. At about 70,000 miles I started to have a hesitation. I changed the spark plugs and wires, the problem seemed to go away and came back 3,000 miles later. Then the check engine lite came on with a cylender #2 miss fire code. I also thought it could have been the fuel system, so I added cleaner and that seems to do the same thing. Fixe the problem for a short distance. An ideas before I take it in for service, I was also thinking about changing the plugs again, or could this be a exhaust problem?

 

i have seen a alot of miss concern's due to aftermarket plug's. mostly bosch, and champion. even the best they make. you may have another concern. but if you have aftermarket plug's. you might want to try motorcraft. i have seen this on alot of diff type's of ford's. they like only certan plug's. good luck. check that plug when you take it out of the cyl. for arching up the side.

 

or swap #1 and #2 plug's and see if you get a change in your miss fire code.

 

It is also possible that you damaged a plug wire while putting them in, see if you can get another wire, just one, from your local parts store. This has been a problem for a lot of people, too. Good luck!

 

i know this post is pretty old.. but my 97 4.2 f-150 just started doing the samething.. ive changed the iac, plugs , plugwires, fuel filter , coilpack and ive put in several diffrent fuel treatments in the tank.. still no fix so if anyone could help me it would be great..
thanks all
-Jay

 

Looking back, I would also recommend changing the plugs again. Maybe that certain plug is missing, and it's the cheapest route if it does fix it, so you may as well try the easiest troubleshooting step first. Good luck!