Any time that you take your truck in for dealer service you should remove any aftermarket engine tuning. It's so easy to detune there's almost no excuse not to, unless you're running a bunch of aftermarket hard parts. Exhausts and intakes should have no effect on the engine's warranty so if you have those mods don't worry too much....if they give you any crap just hold your ground. The cam sensor has been a plague to the 7.3 for a long, long time......there should really be no excuses in regards to replacing it....