I tried to find this as well, with the way they set emissions up, your not going to have it happen. The shop risks too much to allow it. Not to mention its all computerized and on video...
Agree with the second post. A visual check for cats is part of the procedure and the substantual cost and penalties for any of these independant shops to fudge a test is not worth their while - why not just put a cat pipe on it for the test? Many of my friends with off road pipes do this.