The Injen Down Pipe Upgrade Kit with divided wastegate discharge is exactly what your vehicle is craving. Larger diameters, better bends, and a stainless design make for more horsepower, more torque, better flow, less turbo lag, and a happy driver! The part number for this item is SES1204DP and it fits 2008-2014 Subaru WRX, Sti 2.5 + 2015-2017 STI models. This is a RACE Pipe that eliminates the catalytic converter. It is NOT CARB (California) approved and is for Off Road - Race Use only.