2015-18 Ford Mustang Ecoboost Downpipe - Increase performance and improve sound with our Ford Mustang Ecoboost Downpipe. Our Mustang downpipe is designed with a 3" diameter off-road lead pipe. This 304 stainless steel downpipe is TIG welded and fits to the factory connection point. 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 Ford Mustang Ecoboost exhaust, for optimal performance and sound enhancement.