The Injen Down Pipe Upgrade Kit 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! This item also includes an aftermarket hi flow cat to improve performance even further! The part number for this item is SES1202DP and it fits 2002-2007 Subaru WRX, Sti models.