I dont own a RX-7 but my uncle does, an 82 I think, its a Rotary engine, and he wanted me to ask if he can take off the cat and still pass emisions, and also he said the car has a (reactor?) to cool the exhaust? I am not sure if that is correct but that is what he said, and he was worried about this as well, he wants to put a high flow muffler on it, and wants to know if he can do that as well as take off the cat.

 

If your state has emission laws, no you cannot take off the cat to pass, especially if it has
certain hc limits(hydrocarbons). Without a cat on it it will register beyond 2000hc ppm when most limits on idle for this year at least in Ca is about 150hc ppm. You can however put on a quality high flow cat and a good quality muffler that will add hp such as racing beats muffler
and bonez's cat, it also sound much better. rx7docotr

 

Ok, next year the car will not have to take the test, so will heat be a factor if he removes the cat? Also, we both dont know much about the rotary engine yet, so as far as back presure goes, if there is less backpresure will that have any negative effects on the engine?

 

I guess what the main question is, can he take off the stock muffler, put on a higher flow muffler, and then next year take off the cat and be alright?

 

best bet is to get the racing beat exhaust for his year car, and keep the stocker around and put it on for emissions testing.

keep in mind it may not pass even with the stock system with the old *** cat.