If anyone can give me any i insight into this i greatly appreciate it. I have a feeling I am being ripped off. I am have the motor replace in a 2001 Mercury sable with the DOHC motor. I found someone who originally gave me a great price on the labor and i found a low Mileage motor for 600 bucks. Gave shop car and motor. Now 2 weeks later shop is calling saying it will cost more because they have to take plugs, coil pack, intake manifold off of old motor and put on new one. My question is do the parts differ depending on year for the Duratec motors? Mechanic also said someting about firing order being different and I KNOW that has to be a lie. Anyways if anyone can tell me if there are any differences in these motors depending on year i would appertiate it. Thanks.