First things first. I would like to thank all of the contributors on this site. Without y'all (yup, I a' Texan) I would not have been able to repair my truck to its current condition. I have had the p0171 & 0174 codes, completed the gasket and isolator bolt repairs, replaced egr valve, dpfe sensor, cleaned egr ports and intakes etc....truck is no longer throwing codes, but between 1200-1800 rpm's the engine misses or "bucks". I can hear what sounds like an intermittent chirp when I listen to the engine after starting, I am leaning towards a vacuum leak, which I cannot locate for the life of me. I am also considering a coil pack issue, I accidently disconnected a coolant hose during the aforementioned repairs and antifreeze got into the coil pack wire holes. I dried out thoroughly, or at least I thought I did, but am not sure if I could have damaged a coil. Any suggestions would be greatly appreciated, I have become obsessed with fixing this. Truck has 153,000 miles and has been driven fairly passively. Thanks Again.

P.

 

I'd replace the coil pack... whether I'd be COP, CP, or DIST types of ignition, none of them like water. Why?! Think about it... electricity!

 

Do you have a good set of Motorcraft plugs and wires on it?

 

Good point...