The ROUSH Performance Cat-Back Exhaust Kit for the 2015-2021 I4 2.3L Ecoboost Mustang is a great solution for anyone looking for a race-inspired and aggressive tone. Ford's stock exhaust doesn't quite have the aggressive tone or sound Mustang owners crave; this is where ROUSH Performance excels! ROUSH Performance has a specially engineered this exhaust for 2015-2021 I4 2.3L Mustangs. Constructed from 304 stainless steel, this durable exhaust system is corrosion and stain resistant. Mandrel bending has been used during manufacturing to ensure high flow and reduced backpressure constantly throughout the system. This exhaust uses factory mounting points and will fit without requiring any modification or welding. This exhaust system also greatly improves the sound and performance of your Mustang with dual single-tip high-flow chambered mufflers and integrated mid-pipes. Improved sound & performance for 15-19 2.3L EcoBoost Mustangs. Our Cat-Back system made from 304 SS includes a y-pipe & single tip mufflers for that race-like tone. ROUSH Performance recommends checking your local noise ordinance levels prior to purchase. 2015-2018 Mustang 2.3L