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

Hi Jim -- I'm 100% positive there's no negative effect on the engine. I heard this straight from a GM rep and it makes sense. GM doesn't want to sell you something that will sound horrible when AFM kicks in, and they don't want us turning off AFM either. Everyone I've spoken too said it will sound bad with AFM. But the range device takes care of that which as well will not harm anything. Hope this helps let me know if you have any more Q's. Take care, Joe

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.
Thanks
Jim