This Flowmaster Outlaw axle-back exhaust system is specifically designed for 2015-19 Ford Mustang coupes or convertibles with 2.3L eco-boost or 3.7L V6 engines. These systems feature race proven Outlaw mufflers for a very aggressive exterior sound level with a moderate interior sound level. Features include 2.25 inch-connections for an easy fit to the stock mid pipe then the inlets quickly expand to full 3.00-inch mandrel-bent inlet tubing leading into a pair of Outlaw race mufflers for maximum performance. The system is supported from the factory hanger locations for an easy and hassle free installation that can be done at home and is finished off with 4.00-inch brightly polished stainless steel tips for that performance look and sound that you've come to expect from Flowmaster. Covered by our Lifetime Limited Warranty.
Features:
- Large 4 in. Polished Stainless Steel Tips
- Aggressive Race Proven Outlaw Mufflers
- Dyno-Tuned For Maximum Performance
- Large Mandrel-Bent 3 in. Tubing
- Full Stainless Steel Construction
- Easy Installation
Holley Performance Emission Code 5: This part is legal for sale or use on Emissions Controlled Vehicles; Uncontrolled (Non-Emissions Controlled) Vehicles; and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations
Installation Notes:
2015-2021 Ford Mustang with 2.3L Ecoboost or 3.7L engines. Fits coupes and convertibles
About Flowmaster
Manufacturer of performance exhaust systems, mufflers, performance air intakes, turbo boost modules, catalytic converters, race mufflers, headers and numerous exhaust accessories for late model cars, trucks, off-road, Jeeps, SUV’s, classic muscle cars, powersports vehicles and more. Flowmaster® gives you lots of exhaust choices with 12 designs of chambered mufflers, 3 styles of our exclusive “laminar-flow” mufflers and a new line of FlowFX “straight-through” performance mufflers, along with 5 sound categories of exhaust systems, giving you the customer, the power to custom tailor the sound of your vehicle whether you prefer mild, moderate or aggressive tones and sound levels. Since 1983, Flowmaster is the company you can trust, and has led the industry in offering only the best products you can buy for your vehicles.

Vehicle Fitment:
The Vehicle Fitment Guide is to be used as a general reference. The data has been provided by our suppliers and manufacturers and may contain errors or incorrect data. Always refer to a professional to verify correct fitment for your vehicle.
Make |
Model |
Submodel |
Years |
Engine |
Fitment Notes |
Ford |
Mustang |
EcoBoost Premium |
2015 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost Premium |
2016 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost Premium |
2017 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost Premium |
2018 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost Premium |
2019 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost |
2015 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost |
2016 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost |
2017 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost |
2018 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
EcoBoost |
2019 |
2.3L / 140 / L4 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
V6 |
2015 |
3.7L / 227 / V6 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
V6 |
2016 |
3.7L / 227 / V6 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |
Ford |
Mustang |
V6 |
2017 |
3.7L / 227 / V6 |
Dual; Dual Rear Exit; Incl. 3 in. Tubing/Outlaw(TM) Black Mufflers/4 in. Polished 304 Stainless Tips;50 State Legal / California Emissions Compliant |