does EFI live tuning on a truck with the factory warrent stop the warrenty

If it bugs you, you can always get a spare ECM with EFI on it and switch them for warranty work.

ya..then we look at max torque recorded in the tcm the amount of regens for the miles on the truck(if new enough)…then we look at pics from a known good engine running factory cals, and compare wear patterns, injector patterns on piston tops, cylinder wear patterns and many other signs…

Yes, a non factory cal truck can have issues with warranty...