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Flowmaster 2005-2009 Ford Mustang American Thunder Axle-Back Exhaust System 17421

Flowmaster 2005-2009 Ford Mustang American Thunder Axle-Back Exhaust System 17421
Flowmaster 2005-2009 Ford Mustang American Thunder Axle-Back Exhaust System 17421
$639.99 ea
NEWARRIVING SOONEstimated Ship Date 05/29/2025 (If Ordered Today)49 Available from HOLLEY PERFORMANCE PRODUCTS as of 05/09/2025
Model: 4005000
Select a Vehicle or refer to the Vehicle Fitment Tab below to verify that this part fits your vehicle.
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This American Thunder axle-back exhaust system is constructed from 16-gauge mandrel-bent aluminized steel and includes a pair of specially designed 60 Series™ performance muffler with the sound that goes hand in hand with the performance image of the Mustang. The muffler is finished off with large 4.00-inch polished stainless steel tips to fill out the exhaust cutouts in the rear valance for a muscular appearance that matches the sound. As an American Thunder® system, it delivers a moderate interior tone and exterior sound that is suited to the enthusiast who wants their performance to be heard. Like all Flowmaster® exhaust systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, the system includes all necessary parts and hardware for easy installation. Note: Fits both coupes and convertibles.
Features:
  • Includes Hangers and Hardware for an Easy Installation
  • Mandrel bent 16-gauge Aluminized Steel Tubing
  • Moderately Aggressive Exterior Exhaust Tone
  • Dyno Tuned for Maximum Performance
  • 4.00-inch Polished Stainless Steel Tip
  • Uses the Factory Hanger Locations
  • 60 Series Performance Muffler
  • Easy Installation
Fits 2005-2009 Ford Mustang with V6 engine, coupes and convertible models.
Installation Notes:
Fits 2005-2009 Ford Mustang with V6 engine, coupes and convertible models.
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.

Downloads:

Download Name File Size
fm_warranty_general.pdf88.58KB
17421_instructions.pdf1.66MB

Videos:

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
Ford Mustang Base 2005 4.0L / 245 / V6
Ford Mustang Base 2006 4.0L / 245 / V6
Ford Mustang Base 2007 4.0L / 245 / V6
Ford Mustang Base 2008 4.0L / 245 / V6
Ford Mustang Base 2009 4.0L / 245 / V6

Specifications:

2WD/4WD 2WD
California Proposition 65 Chemical Name Chromium (hexavalent compounds), Nickel (Metallic)
California Proposition 65 Required Yes
Color Black
Emission Code 5
Exhaust Series American Thunder
Exit Position Single Rear Exit
Heat Shield No
Inlet Diameter (in) 2.5
Material Aluminized Steel
Muffler Part Number Kit Only
Muffler Quantity 1
Muffler Series 60 Series Delta Flow
Outlet Diameter (in) 2.5
Part Type Exhaust System Kit
Product Type Exhaust System
Proposition 65 www.P65Warnings.ca.gov
Single Dual Single
Sound Level Moderate
System Type Axle-back
Tip Diameter (in) 3.5
Tip Quantity 1
Tubing Diameter (in) 2.5
Warranty Time 36 Months

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Flowmaster 2005-2009 Ford Mustang American Thunder Axle-Back Exhaust System 17421: