I am trying to find a way to disable the DEF system that can be reinstalled. My truck is under warranty and do not want that voided. Unjustly the DEF mode has activated and the clown at the dealership are playing games
Welcome! Stage one tune will do what you're wanting, it will not disable it but gives flexibility to run distilled water in it's place, a full delete is the only option to disable it. Now with that said, what is happening that the dealer is jacking you around on, it's likely the DEF injector needs cleaned.