817587 Flowmaster Exhaust Systems fits 2013 Ford Mustang. 817587 Flowmaster Exhaust Systems Features Immediately boosts performance, sound and MPG with Flowmaster Exhaust Systems. Customcrafted for your specific year, make and model vehicle. Largediameter mandrelbent pipes deliver a restrictionfree exhaust flow. Each kit is powered by Flowmasters legendary highperformance mufflers. Select your Flowmaster system & signature tone American Thunder, Pro Series, dBX Series,, Outlaw Series and Force II (depends on vehicle). Flowmaster Cat Back Exhaust Systems 760 Reviews on Loud Flowmaster American Thunder, Force II, dBX & Pro Series Stainless Steel Dual Exhaust Kits. Flowmaster 817587.