I finally was able to fix a cylinder misfire on my 2003 f150 4.2l

It ended up being the coil pack. What was frustrating was that the coil's primary and secondary resistance all checked out (with an ohmeter). A mechanic at work told me to take it off the engine and look at the back side of it for cracks. It has a "dried caulk-like seal" on the under side. Sure enough, there was a crack under the cylinder that was misfiring. The new coil pack was $60.00 bucks and took less than 15 minutes to swap out.

I guess not to just trust a resisitance check.

I also learned a lesson about reading trouble codes with a cheap obd II scanner. All it told me was misfire on cylinder 2, but I noticed on a list of trouble codes that there are a lot of more specific ones regarding coil packs. I guess a better scanner will give you more specific read-outs.

 

I would not toss the cheap scanner, any scanner will only read the obd II trouble code that the PCM produces. I have a cheap Acutron and a expensive Mac scanner and they will read the same codes for P0 and P1.