Thanks for your help. I just picked up the car. He said that the number on the cat didn't match an original one and thats how they knew. He also said my service engine light is on because the throttle body is not working properly in addition to the cat. So after $115 diagnostic to find the 2 codes of what is wrong I still do not have it fixed since this whole situation with the cat sounced very suspect. I guess I am going to have to go under it and see if I can tell if it is an aftermarket. I would just hate to bring it to another dealer for them to charge me and tell me again that the cat is aftermarket.
