My 08 LMM is in limp mode with no MIL and no DTC's (I suspect a previous owner turned some things off but I don't know what). I bought EFI live to try to figure out whats going on but I'm not exactly sure how to get started with it. I've probably spent 8 hrs watching videos and looking through the program to try and get a feel for it. Kinda scared of it really. I've got the tune from the truck on my computer and loaded but that's about as far as my diagnosing is going. Is there another way to see whats causing the limp mode? Any help would be appreciated.