I had a problem on my Galant where it would cut off here and there while I was driving. It was usually around the time the car would intially start. I took it to the dealer and they wanted $1800. I took it to this other mechanic and all he asked for was $600, BUT he couldn't pinpoint if it would actually fix the problem because he narrowed it down to one of two things. I think the reasons dealerships are always more expensive is because they don't know either. They just replace everything that could be wrong while your normal back alley mechanic will just try and guess what is wrong hence saving you ALOT more than the dealer if they happen to be right. But if they are wrong you probably will wind up paying them around the same amount you could had paid the dealer with less aggregvation. The mechanic told me it could had been some sort of air valve that was bad, or it could had been the entire computer system which was well over a thousand dollars. The dealership I think just rendered both items as toast and figured they would replace both. The mechanic happened to be right it was just the pvc valve, but him telling me he wasn't sure still had me driving on edge the first few weeks after I got it back.