Thanks Simon. I called and they say they may be able to do it if they have the correct software. But they will have to hook up to check. In the meantime I got more info from the Tech that worked on it and it's the infamous P0405 code. He claims that the PCM isn't supplying enough voltage to operate the EGR. Lucky for me, the search function came back with tons of things to try before I go to Biggers Chevy.