3 inch stainless mandrel-bent cat-back pipes and straight-thru muffler cut backpressure by 76%, improve flow by 114%, and add up to 11 hp and 11 lb-ft. Improves acceleration, too! throaty sound, 4 inch polished tip. Toyota Tundra, 5.7L (2009-15), 4.6L V8 (2014-15): Monster exhaust system's 3 inch mandrel-bent pipes are formed of stainless, heavy-wall tubing and bolt behind the catalytic converters, slashing backpressure by 76%. Banks' free-flowing, straight-through polished-stainless Monster muffler has very-high-temperature packing, and is sound-tested to deliver a rich, throaty sound without the annoying drone. The system more than doubles the stock flow, increasing it by 114%. As a result, the Tundra engine is able to produce up to 11 more hp and 11 more lb-ft of torque, which means better acceleration. Reducing backpressure and enhancing the exhaust flow increase fuel efficiency, as well. For an eye-catching finish, Monster flashes a stainless 4 inch rolled-edge angle-cut tailpipe tip in your choice of polished chrome-over stainless or high-temp black! Banks' Monster exhaust system is vehicle-specific for bolt-on installation. Includes: Polished-stainless 3 inch straight-through Monster muffler, Stainless 3 inch constant-diameter intermediate pipe, Y-pipe and tailpipe, Polished-stainless 4 inch angle-cut tailpipe tip with rolled edge, Mounting hardware.