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Flowmaster Force II Cat-Back Exhaust (99-04 GT, Mach 1)

Item 18426
AmericanMuscle no longer carries the Flowmaster Force II Cat-Back Exhaust (99-04 GT, Mach 1). Please check out 2015-2021 Mustang Cat-Back Exhaust for an updated selection.
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    Video Review & Installation

    Hi I’m Justin with, and I’m breaking down Flowmaster’s Force II series catback exhaust, fitting the 99-04 Mustang GT and Mach 1. What makes this kit different to Flowmaster’s American Thunder is the mufflers. The Force II centers around their classic 50’s series mufflers, which is great for someone who enjoys that iconic Flowmaster sound, but without being too loud. This system features 2.5” mandrel bent aluminized steel tubing which Flowmaster enjoys using with a lot of their kits. That aluminized steel is going to be very durable, it’s going to resist corrosion well, it’s also going to help keep the cost down versus more expensive stainless steel. Besides the mandrel bent tubing, we also have the 50 series mufflers, all exiting out these 3” hand polished OE style tips. Since Ford chose to weld the factory exhaust on these cars, you will need to cut it off in order to get started with the install. Once you have that out of the way, getting the Force II installed is a pretty straightforward task, that should take you about 2 hours using basic hand tools. Now let’s hear how Flowmaster’s Force II sounds compared to our factory exhaust.

    Product Information

    Features, Description, Q&A, Specs & Installation


    • Classic Flowmaster 50 Series Sound
    • Durable Aluminized Steel Construction
    • 2.5" Mandrel-Bent Tubing
    • 3" Polished Stainless Steel Tips
    • Includes Two Flowmaster 50 Series Mufflers
    • Fits 1999 to 2004 GT, Mach 1, and Bullitt Mustangs


    Signature Flowmaster Sound. Give your Mustang that unmistakeable Flowmaster sound with the Force II Cat-Back Exhaust system from AmericanMuscle. The Flowmaster Force II Cat-Back Exhaust with its mandrel bent tubing will greatly improve your Mustangs exhaust flow for an increase in power, and the included 50 Series Mufflers will improve your exhausts sound for a deeper throatier muscle car exhaust note.

    Quality Construction. Constructed from mandrel bent 2.5" 16 gauge aluminized steel tubing for it's corrosion resistant properties the Flowmaster Force II Cat-Back features two 50 Series chambered mufflers with 3.0" diameter OEM style polished stainless steel tips for great muscle car looks and sound.

    Application. This Flowmaster Force II Cat-Back exhaust system is specifically designed to fit the 1999 to 2004 GT, 2001 Bullitt, and 2003 to 2004 Mach 1 Mustangs for both impressive looks and sound. This system will not fit the SVT Cobra models.


    CA Residents: WARNING: Cancer and Reproductive Harm -

    Installation & What's in the Box

    Installation Info

    What's in the Box

    • (2) Muffler assemblies/li>
    • (2) Over axle pipes
    • (2) Exhaust Tips
    • (2) Clamps

    Tech Specs

    Cat-Back Exhaust Specifications
    Piping Material: Aluminized Steel Tip Material : Polished Stainless Steel
    Piping Size: 2.5" Tip Size: 3.0"
    Muffler Type: Chambered Fitment: 1999-2004 GT, Bullitt and Mach 1 Mustangs

    Questions & Answers

    10 More Questions

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