Subaru of America, Inc. is pleased to announce the release of the 2008 & 2009 Impreza STI Subaru Performance Tuning Cat-Back Exhaust System. The new three-inch stainless steel exhaust system replaces the stock STI center pipe and rear muffler assembly, and features smooth mandrel bends for low restriction, a better-sounding exhaust note, plus up to a 10 horsepower increase! The Impreza STI SPT Cat-Back Exhaust System is covered by the 3-Year, 36,000 mile Genuine Subaru Accessory Parts Warranty, and may be installed by the dealer, or at the port