2015-2021 Subaru STI Exhaust Systems

GrimmSpeed
Up Pipe 3-Bolt Inlet - Subaru 2002-2014 WRX / 2004-21 STI / 2005-2009 LGT / 2004-2013 FXT | 007064

$39300

Pay over time · Est. $12.28/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

Remark
Stainless Steel Axle Back w/ Single Wall Burnt Tips
Fits: 15-21 WRX/STI

Only 2 left

$69500

Pay over time · Est. $21.72/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
Tomioka Racing
TR Twin Scroll High Flow Catless Downpipe
Fits: 08-14 WRX, 08-18 STI

$75000

Pay over time · Est. $23.44/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

COBB Tuning
COBB EJ Turbo Blanket - Black Lava
Fits: 02-14 WRX, 04-21 STI, 09-10 2.5 GT, 04-13 Forester XT, 05-09 Legacy/Outback XT

Only 8 left

$21500

Pay over time · Est. $6.72/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

IAG Performance
Unequal Length Header & Up Pipe for 2002-2014 WRX and 2004-21 WRX STI | IAG-EXT-1000

Only 1 left

$84999

Pay over time · Est. $26.56/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

IAG Performance
Equal Length Header & Up Pipe for Multiple Subaru Fitments

Only 1 left

$89999

Pay over time · Est. $28.12/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
Up to $79.90 off

In Stock

XForce
Pro Series Catted Downpipe | ES-SW08-KITB
Fits: 08-14 WRX, 08-21 STI

Only 10 left

$71910~~$799.00~~ Save $79.90

Pay over time · Est. $22.47/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
Up to $390.18 off

In Stock

Invidia
Invidia
Fits: 15-21 WRX

Only 8 left

$86100~~$1,251.18~~ Save $390.18

Pay over time · Est. $26.91/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
Remark
SPT Style Axle Back w/ Double Wall Burnt Tips
Fits: 15-21 WRX/STI

$54500

Pay over time · Est. $17.03/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

Remark
Stainless Steel Axle Back w/ Double Wall Burnt Tips | RO-TTVA-D
Fits: 15-21 WRX/STI

$71500

Pay over time · Est. $22.34/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

Remark
Axle Back Exhaust Stainless Single Wall Tips | RO-TSVA-S
Fits: 15-21 WRX/STI

$59500

Pay over time · Est. $18.59/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
Up to $185 off

In Stock

XForce
Varex Valved Cat-Back Exhaust System
Fits: 11-21 WRX/STI Sedan

Only 4 left

$1,66500~~$1,850.00~~ Save $185

Pay over time · Est. $52.03/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

GrimmSpeed
Two Position Exhaust Hanger - 12mm
Fits: Universal

Only 1 left

$2900
In Stock

Remark
Boso Axle Back Exhaust w/ Stainless Steel Single Wall Tip WRX/STI 15-2019

Only 5 left

$69500

Pay over time · Est. $21.72/payment

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Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.
In Stock

COBB Tuning
Silicone Exhaust Hanger 12mm x 35mm
Fits: 08-26 WRX, 08-21 STI, 12-26 BRZ/GR86/FR-S, 05-09 Legacy GT/Outback XT, 14-18 Forester XT

$1500
Up to $285.88 off

In Stock

MBRP
3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street Version
Fits: 15-21 WRX/STI

Only 3 left

$1,21499~~$1,500.87~~ Save $285.88

Pay over time · Est. $37.97/payment

ⓘ

Illustrative estimate only, not a financing quote or guaranteed offer. Actual payments, frequency and terms vary by provider and eligibility. Taxes, shipping and add-ons are excluded.

The EJ257 has one of the most recognizable exhaust notes in the enthusiast world; that unmistakable boxer rumble. The factory system muffles all of it, along with a fair bit of power. This collection covers every Subaru STI exhaust option for the VA chassis: cat-back system replacing everything behind the cat, axle-backs for a straightforward swap with a big sound change, downpipes and up-pipes for owners after real gains, plus mufflers, resonators, mid-pipes, and the hardware to tie it together.

Stainless and titanium construction from Invidia, Grimmspeed, and many more brands with proven fitment on the EJ platform. Verified fitment on every listing means the system you order bolts up the first time.

Cat-Back, Axle-Back, or Downpipe?

Three routes, three different results with your Subaru STI exhaust options.

An axle-back swaps the rear section only. Easiest install, lowest cost, noticeable tone change, but don’t expect power. Right choice if you’re chasing sound alone.

A cat-back replaces everything. Larger piping cuts backpressure across the system, delivering a modest power bump and a fuller, deeper boxer note. This is where most 2015 STI exhaust builds land. The best balance of sound, gains, and cost.

A downpipe is where the EJ257 really wakes up. The restrictive factory downpipe is a genuine bottleneck, and replacing it unlocks meaningful power, especially with a supporting tune. Most performance downpipes are off-road use only and require tuning to run safely.

Going all in with your 2015 STI exhaust? Downpipe first if power leads, cat-back first if sound does.

Sound, Drone, and Living With It

The right STI performance exhaust is the one you still love a year later. And that usually comes down to drone. Drone is the low-frequency resonance that shows up at a steady cruise, typically between 2,000 and 3,000 RPM. On a backroad, you’ll never notice it. On a four-hour highway stretch, it wears you down fast. Resonated systems keep it in check. Non-resonated setups are louder and more aggressive, but your daily commute will remind you of that choice.

Be honest about how the car gets used when deciding on your Subaru STI exhaust option. Daily driver? A resonated cat-back gives you the rumble without the headache. Weekend and track car? Go louder, no regrets. Listen to sound clips before committing, and if you’re stuck between two systems, hit the chat. We’ve heard most of them in person.

FAQs

Will a 2015 STI exhaust fit my 2020 model?

Almost always. The VA-generation STI ran 2015-2021 with a consistent exhaust layout, so systems typically cross the full range. Fitment is confirmed on every listing, and the Garage feature filters for your exact year.

Do I need a tune after installing a Subaru STI exhaust?

Cat-backs and axle-backs run fine on the stock tune. Downpipes and up-pipes require one; running them untuned throws codes and risks real damage.

Is an STI exhaust upgrade street legal?

Cat-backs and axle-backs generally are. High-flow and catless downpipes are typically off-road use only, and emissions rules vary by state. Check your local requirements before ordering.

Why buy from JDMuscle?

Because there was a time when we were on the other end of this. We started in 2019 by modding our own cars and went full-time in 2023. The people picking the brands we carry are the same people who’ve bolted these systems into their own STIs. That shows up in what we stock: proven fitment from brands we’d run ourselves, not whatever has the best margin. Use the Garage feature to filter for your exact year, or chat with us if you want a second opinion before you commit. We'd rather talk you into the right system than sell you the wrong one. Plus: price match guarantee, easy returns, same-day shipping (Saturdays included), and free shipping over $199 to the lower 48.