3" Cat-Back. 2011-2014 Mustang GT/2011-2012 GT500 OEM Conn.

Kooks 3-Inch Stainless Steel Cat-Back Exhaust System for 2011 and 2014 Ford Mustang GT 5.0L & 2011 and 2012 Shelby GT500 5.4L

The Kooks 3-inch cat-back exhaust system delivers the complete bolt-on performance upgrade for 2011 and 2014 Mustang GT (5.0L Coyote) and 2011 and 2012 Shelby GT500 (5.4L supercharged), replacing the factory system from the catalytic converters back with mandrel-bent T304 stainless steel tubing and high-flow straight-through mufflers for dyno-proven gains of 20 and 30 rear-wheel horsepower and 25 and 35 lb-ft of torque while producing an aggressive V8 roar without interior drone.

Featuring polished 4-inch double-wall slash-cut tips and full TIG-welded construction, this system maintains factory ground clearance and uses OEM hangers for direct bolt-on installation with no cutting or welding required. The 3-inch diameter flows significantly better than stock 2.5-inch piping, supporting over 700 HP modifications while delivering classic muscle car sound that complements both the GT and GT500.

For S197 Mustang owners demanding deeper tone and real power gains with daily-driver refinement, the Kooks 11404200 cat-back is the complete solution for street, track, or show.

Key Features

• 3-inch mandrel-bent T304 stainless steel tubing
• Straight-through high-flow mufflers
• Polished 4-inch double-wall slash-cut tips
• Dyno gains of 20 and 30 RWHP and 25 and 35 RWTQ
• Zero drone and aggressive tone only at WOT
• Direct bolt-on using factory hangers

Product Notes

• Fits 2011 and 2014 Mustang GT coupe/convertible & 2011 and 2012 Shelby GT500
• 50-state legal and no catalytic converter changes
• Manual or automatic transmission

California Proposition 65: Contains chemicals known to the State of California to cause cancer or reproductive harm.

Warranty: Limited lifetime on stainless construction to original purchaser.

Installation Notes

• Professional installation recommended lift required
• Bolt-on using factory hangers and clamps
• Torque clamps to 45 ft-lbs
• 60 and 90 minute install time

This Part Fits

Note: Fits coupe and convertible with factory exhaust. Manual or automatic.

What's Included in the Purchase

• 3-Inch Cat-Back Exhaust System
• High-Flow Mufflers
• Polished Quad 4-Inch Tips
• Stainless Clamps and Hardware Kit
• Detailed Installation Instructions
• Part Number: Kooks 11404200

Why Choose Kooks?

• Over 60 years of championship-winning exhaust engineering
• Handcrafted in the USA from T304 stainless steel
• Limited lifetime warranty and dyno-proven performance

Frequently Asked Questions

• Q: Fits GT500?
  A: Yes, perfect fit for 2011 and 2012 Shelby GT500
• Q: Drone on highway?
  A: Zero drone-free aggressive only when you want it
• Q: 50-state legal?
  A: Yes, no changes to catalytic converters
• Do Kooks headers require a tune after installation?
  Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation.
• Will these headers void my factory powertrain warranty?
  Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure. Consult your dealer for specifics on your situation.
• Q: Do these Kooks headers require a tune after installation?
  A: Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation.
• Q: Will Kooks headers void my factory powertrain warranty?
  A: Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure in question. Consult your dealer for specifics.
• Q: What warranty does Kooks provide?
  A: Kooks products are backed by a limited lifetime warranty to the original purchaser against defects in materials and workmanship. Racing and competition use applications may have specific warranty exclusions. Contact Kooks Performance directly for warranty details.

Shipping & Handling

• Method: UPS or Fed Ex Ground.
• Availability: Typically ships same day or next if in stock.
• Packaging: Heavy-duty box with foam protection.