Well I have a bone stock 2011 Duramax that I tuned on my dyno and while I had it I never had a problem with going into reduced power mode. I gave I back to the customer and about two weeks later it started throwing a P0606 code. I then put the stock tune back into it until I could get it back in on the dyno. And by the way it never threw a code with the stock tune in it. I did put the stock tune back in with my MDI not HP tuner. So I will post the tune if anyone wants to look at it and see if there is something I missed. Other than that the truck ran really good, we picked up about 90 hp and 150 in TQ. The egts were about 1280F on a good long pull. Fuel mileage came up too so everybody was happy.
Thanks,
Wade