aFe's Takeda stainless steel cat-back exhaust system brings the power and sound to the 2017 - 2018 Honda Civic Si Sedan with I4-1.5L (t) engine. Constructed from 3" to 2-1/2" mandrel bent, 304 stainless steel tubing improves exhaust flow to deliver up to +10 HP and +11 lbs. x ft. torque. 100% hand TIG-welded by certified craftsmen for race proven strength and durability, the Takeda system incorporates dual, free-flowing 304 stainless steel mufflers to improve performance across the power band while maintaining an aggressive tone and long lasting, good looks. Finished with dual 4-3/4" X 4-1/4" oval black tips etched with Takeda brand logos gives the Civic Si a track-style, custom appearance. Performance Gains: In testing, the cat-back exhaust system resulted in gains up to +10 horsepower and +11 lbs. x ft. of torque, as measured on our in-house dyno. Aggressive Sound: Dual, free-flowing, 304 stainless steel mufflers are used to absorb high pitch tones producing a powerful sound and unleashing more horsepower and torque potential. Dual Round, Double-Wall, Angle-Cut Black Exhaust Tips: This dual rear-exit system features round, double-wall angle-cut, black stainless steel exhaust tips w/ laser-etched Takeda logo for a custom appearance. Installation is a snap: This Takeda exhaust system uses all factory mounting locations providing stability and a hassle-free installation. Perfect Fit: OE-style bayonet hangers are used to maintain a stable pipe location during any driving conditions. The bayonet tip holds the hanger bushing in place for an OE style, long lasting fit. Leak-Free Seal: High quality band clamps are used for a complete 360-degree sealing surface.