Subaru WRX / STI SS 3" Cat-Back ExhaustMFG# 512100 The COBB catback exhaust does not deviate from the factory emissions equipment and conforms to the SAE dictated 95 decibel exhaust noise level limit enforced by California, as well as other states in the US. This system is modeled after the stock exhaust fitment locations, therefore making it an easy direct bolt on item inclusive of all needed gaskets and hardware. The COBB Tuning catback exhaust is heralded often for its quality,