If the main cat has been removed, will this cause any harm? If so will a universal type cat work the type you would get at a parts store?

Thanks!
Bill

 

Do you mean removed and replaced with a straight through midpipe?

A problem can arise if you have too much flow for the wastegate to handle. In these cases, you end up with uncontrollable boost which is called boost creep. This depends on other air flow mods that are on the car as well since not all cars experience boost creep.

Most people don't recommend universal type cats for the hot exhausts of the rotaries. A decent alternative would be a hi-flo cat. More expensive than the cheap local cats but it will also add a little more performance to the car:

http://www.gothamracing.com/catalog/...roducts_id=407

Also, the car will stink without a catalytic converter.