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(12-13-2017 )hhow55 Wrote:  I have a 2010 KW, cm871 that i just purchased a month ago. It has an inframe, with about 60k mi on it. They also replace the turbo, and turbo actuator, egr cooler, egr valve. The engine run's very good. The only thing i am concerned about is is the turbo boost gauge goe's to 42. I have only allowed the boost to go this high a couple time's. It is my understanding the boost should only go to about 36. Also the best fuel mileage i can achieve is 6.0, and this is running the engine very easy, keeping the boost down to no more than 20. Also, all my regen are passive. Sure would appreciate some direction.

With that low fuel milage, even when running easy, what about a leak in the intake/ boost system?? That would cause over boost on the turbo as well as the low fuel milage.