Roush 421127-BLK Axle-Back Exhaust System with Black Tips for 11-14 Mustang GT

Vehicle Fitment

• 2011-2014 Ford Mustang GT (5.0 L V8) - all trims
• 2011-2012 Ford Mustang Shelby GT500 (5.4 L Supercharged V8) - all trims

Features

• Mandrel-bent 304 stainless-steel tubing for high flow and long-term durability
• Straight-through, open-chamber muffler design for aggressive tone with minimized cabin drone
• Dual 4" diameter black-coated stainless-steel exhaust tips with etched Roush logo for premium visual appeal
• Axle-back configuration - retains factory catalytic converters and muffler hangers for simplified install
• Bolt-on installation requiring no cutting or welding; uses original mounting points and hardware
• Designed to increase exhaust flow and throttle response while retaining compliance with factory hangers and clearance
• Deep, aggressive sound tuned specifically for the 5.0 L & 5.4 L V8 Mustangs to deliver race-inspired tone
• Backed by Roush Performance product warranty for manufacturing quality

Specifications

• Part number: 421127-BLK
• Material: 304 stainless steel pipes and mufflers
• Tip finish: Black-coated stainless steel, 4" diameter (each)
• Installation grade: Axle-back only - does not replace catalytic converters
• Fitment: 2011-2014 Mustang GT (5.0 L) & 2011-2012 Mustang GT500 (5.4 L)

Included Components

• 1x left-side rear muffler assembly with black 4" tip
• 1x right-side rear muffler assembly with black 4" tip
• 2x clamps/hangers (as required for fitment)
• Installation instructions

Product Description

The Roush 421127-BLK Axle-Back Exhaust System is engineered specifically for the 2011-2014 Mustang GT (5.0 L) and the 2011-2012 Mustang Shelby GT500 (5.4 L). With premium 304 stainless steel, dual 4" black stainless tips, and an open-chamber muffler design, this system provides an aggressive, resonant tone without excessive drone in the cabin. It retains factory catalytic converters and hangers, making installation straightforward and maintaining emissions-compliance where applicable.

This bolt-on upgrade offers improved exhaust flow, elevated throttle response and unmistakable sound character that complements the Coyote and GT500 supercharged V8 engines. The black-tip styling adds a stealthy, high-end appearance that sets your Mustang apart at the rear fascia.

Ideal for Mustang enthusiasts seeking a performance and style upgrade, the 421127-BLK kit delivers a transformative exhaust sound and look while preserving everyday drivability. Always verify compatibility with your vehicle - including engine size, model year and trim - before installation.