I ended up having to replace the plugs and coil-on-plugs (or, rather, replaced all 8, like you would use to do on a 'tune up'), and it fixed all issues. My poor V8 was likely running on 6 cylinders before. It's an expensive tune-up, and the parts, themselves, are 300-ish, as opposed to the 50 the old plug/wires would have been in the past. The BAD news is, if you have the two-piece design plugs, they can, and one or two of them might, break off. If that happens, most shops will charge you about $100 per plug that breaks off. I'll just say, after having had to fish one of those out of a head, it's worth it. BUT, you don't want to have to pay for that, if they break off 8 of them, while changing your spark plugs.
Find a reputable shop, that will do the work, and, at minimum, split the cost with you, if one breaks off.
WTF Ford went with a 2-piece spark plug design is still a question of WTF were they thinking. Just hope none break off. But I guarantee, if you're having the wrench, and you have a V8, it's because it needs new plugs/coil packs. changing them at 125K miles righted my truck immediately!
