we dont have to pass a test here, but the stuff has to be there. to pass a test i would think you would have to have the whole ball of wax. conv. air pump and egr valve all hooked up. if you have some test to pass, having 2 conv. on a gm is as bad as not having one at all. its want pass with 2 conv., next ? is if you dont have a test to pass why would you put 2 conv. on anyhow? just asking.