Im working on my friends 2002 3.8L v6 mustand that has a cylinder 3 misfire code and runs really rough. He put new plugs, wires, and a coil on it and same issue. I started unplugging wires off the coil when it was running and cylinders 3 and 4 are getting no spark out of the coil. Cylinders 3 and 4 are matched pairs also. My next step was the ohm the wires from the coil to the pcm but I wanted to hear ideas from other people. I have heard of a couple pcm's going bad causing a misfire and a bad crank postion sensor also but no code for that. The codes im getting are a p0351, p0352, p0353, p0316, and a p0303 but I think most of them are from me unhooking the wires when it was running.

When I ran the koer self check with the engine running the p0352 code comes up with a p0505 iac code.

 

Check out www.v6power.net tons of v6 stang help there. I think there is even a sticky on the misfire issue.