Valvetronic Design Audi B9 S4 / S5 Valved Sport Exhaust SystemWelcome to a sound revelation for the Audi S4 B9 Platform. With such a potential powerplant, the EA839 3. 0 L V6 hides a truly incredible set of vocals behind the heavy and restrictive factory exhaust equipment. With the Valvetronic Designs full exhaust system, we ensure this incredible powerplant sings all the way up to the redline. Traditionally, in the audi exhaust market, there are many different pieces of the exhaust that you have to purchase