I'm new to the Duramax world, been looking for a LBZ for two years now and finally bought one. 2006 LBZ 3500 4WD DRW. Truck has 69k miles on it, S&B air intake, straight piped 4" exhaust, and a Duramaxtuner DSP5. With everything done to it, I'm getting roughly 15-16 mpg and honestly I'm not impressed with the power it puts out in any of the settings. On top of that, there is a code thrown for "overboost" from the turbo. Two of my close friends have LBZs with Bully Dog tuners and nothing else done to the trucks and theirs seem to have more performance and fuel economy. I'm Looking for any knowledge and opinions on tuners or the other modifications to the truck and any knowledge on how to fix the "overboost" code. Any help is appreciated!