First of all cattless DP are going to throw a code without simms and if you don't have a tune (I don't think you want that on at the dealer right), you have a problem because the ECU will throw SES CEL. And then there is the very very obvious sound alteration they will clearly hear. These are people who are sorrounded by these cars all day every day. Do you think they can't tell? Then checking is damn easy. the pan takes a minute to unscrew with a proper lift. They can tell even just driving it from the lot into the bay, trust me on that one. There is no hidding these mods at the dealership. If its there, they will find it, and then its up to them if they should let you slide.
Brazenly taking a car there with mods on, is insulting to them and asking for it.
