With an increased flow capacity, the Billy Boat Performance Exhaust system introduces increased mid-range and top-end performance and lends a crisper, more commanding exhaust note without being intrusive. Headers and mufflers for the 996 are available together as a kit or separately. All emission devices are retained and the system is OBD-II compatible. There is no modification necessary for installation as the headers and mufflers are a direct replacement for the factory exhaust equipment.