that's not really answering my question but anyways. Ive had no tune with a full exhaust system put on. no engine lights and an electronic boost controller. And everything is tip top. had it on the dyno everything is great. Touch wood. The boost controller is stopping any overboost and no engine lights are on from cat change or exhaust change. and running better than ever. sorry for hijacking the thread guys just sharing my opinion. EDIT: I have a tune for all my prevous mods obviously just no recent one for exhaust.