• 15+ Years of Performance Parts, Tuning & Installation

STM WRX/STi 2015-2020 Axle-Back to Cat-Back Upgrade

  • Backed by real installs and tuning experience at FAST of West Chester

Everyday Low Price:

$720.00
$720.00
Shipping calculated at checkout.

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Earn FAST WC Points on this order — redeem on your next purchase
If you already purchased the STM Axle-Back Exhaust, you can purchase the rest of the cat-back system separately for a full upgrade! This *should* also be compatible with many other aftermarket axle-backs that have a 2.5" flange and bolts to the stock locations, but please confirm before purchase.

The STM Stainless Steel Cat-Back Dual Exit Exhaust for the 2015+ WRX and STi will bolt up to your stock or aftermarket downpipe and gives you everything you want out of a catback exhaust! Full stainless steel construction, gorgeous design and hand-fabricated in the USA. The STM Exhaust utilizes your existing exhaust hangers and includes all gaskets and hardware for a clean and easy installation.

Vehicle Fitment:
2015-2020 Subaru WRX
2015-2020 Subaru STi

Install Notes:
We include 5 gaskets for this 4 gasket install.
• (1) 3" and M10 hardware for the center pipe to axle back
• (2) 2.5" and M10 hardware for the axle back to tips
• For the cat-back to stock downpipe use the 2.5" gasket and M8 hardware
• For the cat-back to 3" aftermarket downpipe use the 3" gasket and M10 hardware

Features & Specs
• 6.7 Pounds Lighter than Stock
• Tig Welded
• Back Purged
• 3" Piping to The Y
• 2.5" Piping From The Y to The Tips
• Mandrel Bent
• Full Stainless Steel
• Tig Welded
• Back Purged
• Gaskets & Hardware Included
• Bolts to Factory Locations
• Beautiful Fit and Finish

STM Products are made in the USA!
Lifetime Warranty on STM Parts to the original purchaser against manufacturing defects.

Includes:
(1) STM Stainless Exhaust (Mid and Y Pipes)
(2) 3" Remflex Gaskets
(2) 2.5" Remflex Gaskets
(8) M10x35 Bolts
(8) M10x1.5 Nuts
(2) M8x30 Bolts
(2) M8x1.25 Nuts

Shipping Times: 4-6 Weeks
Hand crafted and welded in New York, please give our fabricators time to create your piece!

See more STM Parts
See more STM Products
  • Earn FAST points on this part!
  • Backed by real-world installs
  • FAST WC Team Approved
STM WRX/STi 2015-2020 Axle-Back to Cat-Back Upgrade

$720.00

Why Drivers Choose FAST of West Chester

  • I can't recommend this place enough. Being able to trust a shop in the performance world is big. The 2hr drive to get there, is worth knowing the job will be done right. Very happy to have found this shop, to
    support my builds going forward.

    Donald Wojnar

  • I recently had the pleasure of working with FAST of West Chester for some performance upgrades on my 2022 WRX, and the experience was nothing short of exceptional. I opted for a Borla S-Type exhaust and Cygnus Coilovers, and the team at FAST nailed the installation, fitment, and setup to a T.

    Adam Cranston

  • The team at FAST are excellence in every way. First, I consulted with Dave on mods for my HPDE track car. He listened and advised me on the best parts & mods to achieve my goals. He was patient & gave me space to research the options presented & worked with me through several changes before we built. Second, the build execution was flawless, proper heat shielding, bracing and poly everywhere. All components worked as advertised.

    Bryce Budd

  • This place has been my go to shop for all things Subaru. From simple service to performance parts and tuning, they have been top notch.

    William Brunell

  • Excellent shop. They installed a Cobb Stage 2 DP and Whiteline Sway bars and end links on my 2013 WRX. The work was done right and clean. The estimate was accurate. They were very knowledgeable, friendly and gave me the straight scoop on exactly what I was getting for the money
    and what I needed to get where I want to be with it. I'd recommend them
    to any car enthusiast.

    Devin Greco

Does it come with a warranty?

Most products we carry include a manufacturer warranty. Since we work with top performance brands, warranty coverage can vary by product. If you have questions about a specific item, reach out — we’re happy to help.

Do you offer installation help or advice?

Yes — we don’t just sell parts, we install and tune them too. FAST of West Chester is a real performance shop, and we’ve worked hands-on with many of the products we carry. If you have questions about fitment, installs, or building your setup, our team can point you in the right direction.

How fast is shipping?

Many of our products ship the same day or next business day, depending on availability. We work hard to get parts out fast so you can get your build moving without delays.

What’s your return policy?

Returns for exchange or refund are accepted within 30 days of receiving your order. Items must be in new, unused condition and in original packaging. If you have any questions, our team will help make the process easy.

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