Put it this way, I crossed my spark plug wires while changing the plugs on my '95 duratec. Results? After driving it 12 mins away to my brothers to help me sort out my debuckle, I cooked the pre-cats. The engine in turn ingested enough debris that cause me to run thru a quart of oil every five days. I unloaded that car real quick. But all good things come to an end. I wound up buying a '98 SVT. Fun to drive, yet not gonna last the 5 year loan I got out on it.