KYOSTAR 76mm Valved Catback Exhaust System w/ OPF for BMW S58 3.0T The KYOSTAR 76mm Valved Catback Exhaust System is designed specifically for OPF-equipped BMW S58 models, providing improved exhaust flow while maintaining full compatibility with factory OPF emissions equipment. The electronically controlled valve system allows you to switch between a refined daily driving experience and a more aggressive exhaust note under spirited driving conditions. Constructed from premium