Rob: I was at the e test business yesterday, talked with the owner. He said if you can get your state of tune reasonably close to stock it will be just fine. It has to be able to run the dyno load test for the required duration without kicking out too much heat basically. If a check engine light comes on during the tread mill run, then they have to fail as well. The DM's generally don't give them any trouble because of the variable rates of tune. Permanent chip type instals are an issue.
Trucks manufactured with a cat on them must have it on when they show up for the visual inspection.