I was just playing around with my truck, 2004.5 LLY with edge w/ attutude system. When I am running in 1,1 I am getting a knocking noise from either engine or turbo, sounds to me more like turbo. The only way I could desribe it is like a spark knock on a car that is not timed right or running the wrond fuel. It is only at 1800-1900 RPM's. Has anyone else experienced this?? If I change it to 1,2 it will go away!!! Kind of wierd if yo uask me!!

I have same truck and have noticed it as well. Sounds like you described. I thought it was bad fuel. It has happened a few times but I have never been able to duplicate it. I run mine at level 1 90 percent of the time.