Thanks for the info, any and all is sincerely appreciated. My Contour has 120,000 miles on it. Incidently, I am sure I know when and how the pre-cats were clogged. My mechanic cleaned out the EGR ports on the car by scraping, brushing and spraying cleaner in the ports. Their comment was, "Man, the black smoke really rolled when we started her up and let her run." I have little doubt as to this being the end. One more question for someone, my mechanic has already stated that they will most likely have to jack the engine up to get to one of the manifolds. True or false?? Again, Thanks.....Steve