2015-2018 Ford Mustang Ecoboost Downpipe - Increase performance and improve sound with our Ford Mustang Ecoboost Downpipe. Our 2015-2018 Mustang downpipe is designed with a 3" diameter catted lead pipe. This 304 stainless steel downpipe is TIG welded and fits to the SW Ecoboost Mustang exhaust. Get superior performance with a lifetime guarantee with Stainless Works. Available with a variety of options: Choose from our high-flow catalytic converter or off-road lead. Also choose your connection point: Factory Connect easily mates to the factory connection point (to the factory exhaust), or Performance Connect, to pair with Stainless Works 2015-2018 Ford Mustang Ecoboost exhaust, for optimal performance and sound enhancement.