Hi Joe---I feel pretty stupid, but what is a range device? Did you try it first without this range device? If you did, how did it sound when the AFM kicked in? It seems like you wouldn't hear it at highway speeds anyway.
I really appreciate the help with this and you're patience with me.
Thanks again-- Jim
Are you sure that exhaust doesn't have any negative effects on the engine or it's components? It just seems strange that GM wouldn't want to sell those components just because they don't sound good when the AFM kicks in. At highway speeds, you probably can't hear it anyway.