Ok because I live in the great state of CA, I have to smog My 88 S4 t2 that has a racing beat 3" down pipe to custom exhaust out the back, No muffler shop will sell me just the Main cat and install it into my system, So I want to buy an aftermarket cat that is 49 states legal, and that will pass the Ca seal of approval. does any one have any suggestions... I was gunna go magnaflow, but will it hold up to extra fuel and heat that a rotary will produce an what I'm going to throw at it . So who makews good ones and where can I get them ? Plerase help I have to smog the Monster in less than a month .

 

Bonez HI FLO?
they should make a 3 Inch in and out.
Check Rx7store.

 

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/fc-catalytic-converters-917309/