I am new to efi live but not HP tuners. My brother and I have both. I read through all the forums concerning the upgrade and when I upgraded my os last night, the reduced power light was on and it would barely idle. I havent figured out how to change engine segments and I have no clue how to use .cax files because my goal is to eventually get lean cruise enabled because I want to try to hit 25-30 on the highway.
Andrew Clark 00 Yukon XL stock 5.3 4x4.tun
2002 GMC Yukon Truck Automatic L59 (Custom OS for Andrew Clarks 00 Yukon).tun
Edit: forgot to add I had a few codes. One was TAC module communication error, which my Yukon is cable throttle. And the other had to do with a fuel sensor error.