2015-2021 Subaru STI Exhaust Systems

    307 products

    Clear all
    • Up to $390 off
      In Stock
      Invidia [08-14 WRX/ 08-21 STI] High Flow Catted Downpipe | HS08SW1DPC
      Invidia

      High Flow Catted Downpipe

      Fits: 08-14 WRX, 08-21 STI

      $86100$1,251.00 Save $390
      Pay over time · Est. $26.91/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.

    • In Stock
      GrimmSpeed Turbo to Downpipe Gasket - Subaru Turbo
      GrimmSpeed

      Turbo to Downpipe Gasket

      Fits: 02-14 WRX, 04-20 STI, 05-09 Legacy GT/Outback XT, 02-13 Forester XT

      $2900
    • Up to $129 off
      In Stock
      Tomei [08-21 WRX Sedan, 11-21 STI Sedan] Expreme Ti Titanium Catback Exhaust | TB6090-SB02C
      Tomei

      Expreme Ti Titanium Cat-Back Exhaust - Sedan

      Fits: 08-21 WRX, 11-21 WRX STI

      Only 4 left
      $1,16100$1,290.00 Save $129
      Pay over time · Est. $36.28/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.
    • Up to $40 off
      In Stock
      Blox Racing [15-21 WRX/STI] Stainless Steel Axle Back w/ Single Wall 3.5 Inch Polished Tips | BXEX-51104
      BLOX Racing

      Stainless Steel Axle Back w/ Single Wall 3.5 Inch Polished Tips

      Fits: 15-21 WRX/STI

      Only 20 left
      $28900$329.00 Save $40
      Pay over time · Est. $9.03/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.
    • Up to $4 off
      In Stock
      Turbo XS [WRX/STI] OEM Downpipe to 3in Cat - Back Adapter w/Standard Exhaust Gasket | ADA - OEMDP - 3CB - JDMuscleExhaust Gaskets and HardwaretxsADA-OEMDP-3CB
      Turbo XS

      OEM Downpipe to 3in Cat-Back Adapter w/Standard Exhaust Gasket

      Fits: WRX/STI

      $3500$39.00 Save 10%

    • In Stock
      GrimmSpeed Uppipe to Turbo Gasket
      GrimmSpeed

      Up Pipe to Turbo Gasket

      Fits: 02-14 WRX, 04-21 WRX STI, 05-09 Legacy GT, 04-13 Forester XT

      $2600

    • In Stock
      JDMuscle 15-21 WRX/STI Tanso Carbon Fiber Exhaust Trim Covers
      JDMuscle

      Pre-preg Carbon Fiber Exhaust Trim Covers

      Fits: 15-21 WRX/STI

      Only 7 left
      $22900
      Pay over time · Est. $7.16/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.
    • Up to $742.36 off
      In Stock
      Invidia [15-21 WRX/STI] Gemini R400 Titanium Quad Tip Exhaust | HS15STIGM4ST
      Invidia

      Invidia

      Fits: 15-21 WRX

      $1,63400$2,376.36 Save $742.36
      Pay over time · Est. $51.06/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.
    • RES X JDMuscle 15-21 WRX/STI Valvetronic Catback Exhaust MT&CVT
      JDMuscle

      RES X JDMuscle Valvetronic Catback Exhaust MT&CVT *Special Order*

      Fits: 15-21 WRX/STI

      From $2,37000
      Pay over time · Est. $74.06/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.
    • Up to $89 off
      In Stock
      Tomei [02-14 WRX, 04-21 STI, 05-09 LGT, 05-08 FXT] Unequal Length Exhaust Manifold/Header
      Tomei

      Unequal Length Exhaust Manifold/Header

      Fits: 02-14 WRX, 04-21 STI, 05-09 LGT, 05-08 FXT

      Only 5 left
      $80100$890.00 Save $89
      Pay over time · Est. $25.03/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.
    • Up to $697.72 off
      In Stock
      Invidia [15-21 WRX/STI] Gemini R400 Stainless Steel Quad Tip Exhaust | HS15STIGM4SS
      Invidia

      Invidia

      Fits: 15-21 WRX

      Only 16 left
      $1,53500$2,232.72 Save $697.72
      Pay over time · Est. $47.97/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.
    • Up to $525.10 off
      In Stock
      Invidia [15-21 WRX/STI] N1 Dual Cat-Back Exhaust - Titanium Tips
      Invidia

      N1 Dual Cat-Back Exhaust - Titanium Tips

      Fits: 15-21 WRX/STI

      Only 10 left
      $1,15700$1,682.10 Save $525.10
      Pay over time · Est. $36.16/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.

    • In Stock
      Remark [15-21 WRX/STI] Mid Pipe Kit Non Resonated | RO-CPVA-N
      Remark

      Mid Pipe Kit Non Resonated

      Fits: 15-21 WRX/STI

      Only 10 left
      $75500
      Pay over time · Est. $23.59/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.
    • Up to $401.20 off
      In Stock
      Invidia [08-14 WRX, 08-21 STI] High Flow Cat w/ Extra 02 Bung Downpipe | HS08SW1DOC
      Invidia

      High Flow Cat Downpipe with Extra O2 Bung

      Fits: 08-14 WRX, 08-21 STI

      $88400$1,285.20 Save $401.20
      Pay over time · Est. $27.63/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.
    • Up to $401.20 off
      In Stock
      Invidia [08-14 WRX / 08-21 STI] Downpipe w/ High Flow Cat | HS08SW1DOCB
      Invidia

      Catted Downpipe w/ High Flow Cat

      Fits: 08-14 WRX, 08-21 WRX STI

      $88400$1,285.20 Save $401.20
      Pay over time · Est. $27.63/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.
    • Up to $156 off
      In Stock
      PLM Power Driven Subaru EWG Up Pipe with Dump Tube 44mm - JDMuscleTurbo UppipesPLM-SUB-UP-PIPE-EWG-44MM
      Private Label MFG

      PLM Power Driven EWG Up Pipe with Dump Tube 44mm

      Fits: 02-14 WRX, 04-19 WRX STI, 04-06 Baja Turbo, 04-13 Forester XT, 05-09 Legacy GT, 91-94 Legacy Turbo, 05-09 Outback XT

      Only 7 left
      $33900$495.00 Save $156
      Pay over time · Est. $10.59/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.

    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.