B_WALLACH

Hello, I want to adapt a pipe to the header where the cat. converter is mounted to. Does anyone know what the size of the collector is or what size exaust pipe would fit up to the header's collector? As a guess I'd say 2.5".
I would prefer to find out this way instead of taking it apart to measure it, just a bit lazy I guess and will appreciate the size of this very much.
Oh yeah, the car is a 86 4000CS Quattro.
Don't tell the law but I am thinking of removing the cat.. They don't test exaust where I live so I can get away with it out here so I'm thinking of making a short piece of pipe to bolt in where the cat. is in the exaust. The tricky part may be making a mount for the Oxg. senson but I think I got that part worked out. I don't know if it will do much for the performance or not but it's something I just want to play around with and see what happens... thanks for any help..

JeromeS.

Yeah, its 2.5". Funny thing about removing the cat, is its not 'a huge polluter' on our cars. A guy I met in the area has an 87 4kq, with a hollow cat and he passed emissions! I was amazed to say the least. I think its easier to just hollow one out instead of fabricating your own test pipe.

B_WALLACH

Your right, I've been thinking about doing that as well, it would save me trying to fab. a mount for the Ox. sensor. Thanks for the size though. I've also been trying to think of every way to remove extra weight and wonder how heavy those cat's are? It may be picky but every bit helps and I also wonder about the turbulence of the exaust going though a gutted cat also, if it may mess up the free flow of the exaust that way but it's all just guessing as I've never looked inside of a cat before. Thanks lots for the help...