I only know a thing or two about lb7s so that is why I ask the pros. My uncle has an 05 duramax and just put on an exhaust system. He is trying now to get rid of a whining sound out of the exhaust that happens at idle and even when he revs it. The sound starts about 3-4 seconds after the truck starts it disinctly comes on. I personally like the sound but he hates it. I was wondering if it the egr or something to do with that. Can you get rid of the sound. Would an egr blocker plate do it. Do you throw codes if you unplug it to check or can you unplug it to check. Can you turn it off with efi live? Im trying to help him so any help would be greatly appreciated. Thanks kevin

sounds like the turbo.all kinds of sounds come out when you change the exhaust.putting in a blocker plate will only change the pitch of the sound.

I love hearing the turbo spooling up on my truck. That was the first thing I noticed when I put the exhuast on that you could hear, not to montion the exhuast note.

It's the VVT changing the blade pitch. Totally normal. You can get rid of it if you use EFILive.

You could remove the new system, and I'll come pick it up so it doesn't take up any space in his garage:angel:

It's the VVT changing the blade pitch. Totally normal. You can get rid of it if you use EFILive.
How?