My GSR came with a full Comptech Cat back exhaust and in the trunk was what I assume is a Comptech high flow cat. My problem is that it only has one O2 bung at the header end and no sensor bung at the exhaust end. is there something I dont know or is it just the wrong cat? Its the right length and has the right bolt patterns. Any help is appreciated.

Thanks for helpin a Newbie out. :-D