The GT exhaust is a reworked original exhaust, modified in our workshop. It looks just like stock on the outside but the internals are changed to a better breathing, less restrictive exhaust. The original mufflers are modified internally resulting in a louder and deeper sound with no reasonance. This exhaust does not trigger check engine lights and is not giving problems with emission checks during the yearly technical inspections like MOT, APK. The modified exhaust looks 100% original on the outside.