I am posting this question for a friend that has an o2 ctd with a auto trans. She is need of more power for towing and would be very happy with something along the lines of an edge ez or power puck. She called our local dealer and asked how adding one of these mild performance boxes would affect her warranty and they replied, warranty both engine and drivetrain will be void. Is this the correct dealer response? Is it true that codes would be stored so they could tell if she had added performance enhancements? Could she upgrade with say some 275's for some additional power that would be unnoticed by the dealer? I am my own warranty station but I would like to give her accurate info. Thanks for any insight.