first off our cat is inside the engine bay not under the car, and welded to the cat on the back side is about 3 feet of bent pipe befor it connects to the flex pipe which starts by the front wheels and goes up and through a bunch of junk then back down to connect to the "cat-back" system which in out case is truely a Flex-Back system.
and if you look at the escort header we would use, it is a long pipe design and goes straight past where our cat is, so to just bolt right up to our cat you would have to chop up the tail end of your cat plus the new header plus your old manifold which I don't think you can do.
there are two simple ways to go about this (assuming you can put the Cat after the flex pipe)
1) put an escort flange on our stock flex pipe to connect to the escort header, cut off both sides of the cat-converter and put on the flange that connected the muffler to the flex pipe on the front of the cat, and get a donoy flex pipe from any zetec or SPI focus and cut off the back flange and put that to the back of your old cat which is now after the flex pipe, so you can bolt up any cat-back system and actually have a cat-back system (but you will have to cut off a few inches of it before the muffler, maybe not if you get the zx3)
2) put the flange from the back of our cat onto the escort header to bolt up to our flex pipe, put the flange from our muffler to the front of the cat and use a focus donor flex pipe as the flange on the back of the cat, to bolt up to any cat-back system (again you would have to cut off some ammount for it to fit, maybe not if you get the zx3)
There is one other solution, but I'm not sure it would work, it's just an idea that poped into my head just now-
-cut off both ends of the cat so it's straight (or just buy a new universal one)
-cut the new heder right after the third collecter (when it is just one pipe)
-weld the cat on
-weld the flange from the end of the cat on right after the car to eliminate the un necessary bends and to bolt diretly to the flex and back
^^^come to think of it this IS the easiest of the solutions, but it's a clearence issue now, hopefully there is enough room from the third collector to the flex pipe to fit a cat, then hopefully it won't scrape the ground on lowered cars.
*If and when I eventually do try to put escort headers on I'm going to do this last version, it sounds like the best solution to me, and if I get an aftremarket universal cat, I can get a round one and hopefully shorter so it will fit and allow for more clearence!
wow, Playa, you keep me thinking! keep finding problems with it make sure I'm not forgetting anything
I still have a Focus parked, I might fix it up one day.