BaFe 49-36306 Mach Force XP CAT Back Exhaust System for BMW 335i 2011 L6-3.0L ReviewbP PP aFe 49-36306 Mach Force XP CAT Back Exhaust System for BMW 335i 2011 L6-3.0L PProduces 11 horsepower, 13 pounds by feet of torquePConstructed from 2.75 inch mandrel bent and high polished 304 stainless steelPAlso includes dual high flow resonators and dual 3.