I emailed Bully Dog about this very same question earlier this week and this was the reply:
Brian, let me thank you for visiting our website and being a current
bullydog customer!
Q: I Would Like To Know How To Get My Power Pup Upgraded To The
> Extreme Setting.
A: Your power pup should come with 4 settings, stock, tow, performance, and
extreme. I think you may be talking about the high hp upgrade we used to
offer on the old power pup for the Duramax that has been discontinued and no
longer available. Any time you plug it in you should be able to choose the
level and hit yes to put it in that mode but if you are talking about the
150hp upgrade then it is no longer available for that truck, Thanks Jason.
Jason Schedule (Technical Support& Inside Sales)
(866)289-5362 toll free, (972)201-2681 local
[email protected]