I pulled a code on the truck (1997 F150 4.6 ltr 105K), P0308. #8 Cyl misfire. I can hear some exhuast noise (like a cracked manifold) could this cause this code? The check engine light ocassionaly goes out and then back on. There is a rough (though not that bad) idle.

 

Check your plug wires. That code is number 8 misfire. You might have a bad plug too.How old are your plugs & wires?

 

Make sure the plug is tight and not about to blow out of the head!!!!

 

I found a loose wire on the distributor end, under the air filter. I cleared the code and it has not come back. I still hear the exhaust noise, and cannot find the source, the truck is idling better.

The plugs and wires are original after 106K. Got a bit intimidated while considering replacing them, read some articles. Still not convinced that its a job worth doing, looks like a bunch of hoses, wires and stuff still needs to be removed!

Thanks for the help, the IAC, #8 plug problem and the transmission are all giving me trouble at the same time!