aFe is proud to introduce the aFe dual cat-back exhaust system. In recent testing this aFe cat-back exhaust system produced 34 horsepower and 43 lbs. x ft. of torque, furthermore, weighs 20 lbs. less than the stock exhaust. With the iconic 911 already a well-engineered performance driving machine, aFe developed the perfect balance of pure, race-inspired performance while ensuring that perfect sound decibel and exhaust note creates the ultimate driving experience. Starting with a CAD X-Pipe, aFe spent countless hours of R&D to ensure that the volume, flow and balance was no less than perfect. Also, aFes unique brushed finish step mid pipe design unleashes all available power and creates a broad and exciting power band. Included are dual 304 stainless steel light-weight race mufflers and resonators, this straight through design eliminates any restriction and optimizes maximum power and performance with no compromise. Available with 3.5 in. polished 304 stainless steel quad tips and CNC-Machined laser-etched tip inserts, this system is hand-crafted and TIG-welded for a perfect, precise fit and 100% complete bolt-on installation. No modifications necessary. MACH Force-Xp 2-1/2 IN 304 Stainless Steel Cat-Back Exhaust w/Carbon Fiber Tips Porsche 911 (991) 12-16 H6-3.4L/3.8L Porsche 911 (991) 12-16 H6-3.4L/3.8L