2006 mustang gt
I have a 2006 mustang 4.6 gt engine. It has a code cylinder 5 misfire. The engine that was in it when this started had 178,000 miles on it. I found it had a blown head gaskets. So I figured that as long as I would have to remove the engine to change the head gaskets it would be best to replace the engine. So that's what I did. The problem is still there. Everything has been replaced and tested. Is it possible that this could be a relay issue where the computer and relay are not communicating properly. As it actually makes the engine misfire?