Try changing the wires first. If you do a search of the forum, you'll find many threads that talk about the Bosch plugs. They're probably good plugs in other cars, but they just don't work well in the Duratech. I actually had them in my car and they did last for about 25k but then went south quickly. The consensus on the forums is that Motorcraft or Autolite plugs are the way to go.
