Injen (SES9001TT) Cat-Back Exhaust System with Injen Embossed Muffler and Dual Burnt Titanium Tip Potential Torque Gains: +15 Potential Horsepower Gains: +17 2013 Focus ST 2.0L 4 cyl. Turbo- Full 76mm S.S. cat-back system w/embossed Injen muffer & dual burnt titanium tips