I am just starting to tune and diagnose things on my 2007 6.0. I got the new mpvi2 tuner. When i connect to the truck, which i can only do through USB, I only get a few datastreams or channels to work. Simple ones like voltage rpm,ect,map,speed IAT, thats about it. I add them before hand but no data populates when the engine is running. Also, I have a check engine light on the dash yet the scanner wont show any codes when i try to retrieve DTC's. What am I doing wrong here? What further info can i provide to help? Ive done some tuning with HPTuners on LS based chevy stuff and have never had this problem.