I've searched, and just want confirmation that I can't run just one cat on my stock 85 GS. The stem broke off the Split Air pipe at the cat and trying to figure out a way to run without the Split Air pipe which means I need the factory cat if it won't work. The system from exhaust manifold to cat back is pretty rusted, but don't have too many funds for RB or something else custom right now. Thanks in advance.

 

http://www.rx7.com/store/rx7/saexhaust.html

 

Naive, looks a lot cleaner than the 3 on there now

 

I have a post running about my Bridgeport on the build thread, and in it we talk about the exhaust. Ironically, my split air pipe also rusted out, But I just ended up removing all of the cats [ALL OF THEM] and replacing them with my own ghetto welded straight pipe as a temp replacement. I don't currently have anything hooked up to the hose attachment on the intake side, but it seems to work ok.

 

Eventually I too want to get rid of the cats, but here inNC, still need to pass inspection until it's 35+ years old. I ended buying a stock cat and eliminated the 2 pre cats. So far so good.