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WRX Cat-back exhaust

Your WRX

Pick your year to see what fits.

This page covers the WRX and STI. The non-turbo Impreza has its own page.

+3–10 whp (est.)
Medium$835–$1,6201–2 hrs
All WRX mods

Why do it

Replaces everything behind the downpipe for better sound and less weight.

Tools you'll need

Starting out? See our budget tool list.

Parts to buy

Double-check fitment before buying. We may earn a commission when you buy through these links, at no extra cost to you.

Before you start

  • Soak the old bolts in penetrating oil the night before.
  • Check your new exhaust's fit before you unbolt the old one.
  • COBB lists a tune as needed after this exhaust.

Steps

  1. Plan the job

    • Lift the car, look at how the stock exhaust is hung and lay out the new parts.
    Watch this step (Epoch Motoring, on a 2007 WRX) (3:01–5:12)

  2. Remove the factory exhaust

    • Undo the flange bolts and slide the pipes off their rubber hangers.
    Watch this step (5:12–10:35)

  3. Fit the new system

    • Hang the new pipes, use new gaskets and loosely bolt everything up.
    Watch this step (10:35–17:27)

  4. Adjust and tighten

    • Line up the tips, then tighten everything front to back.
    Watch this step (17:27–21:15)

  5. Unbolt the muffler section

    • Remove the two bolts joining the muffler section to the mid-pipe.
    Watch this step (GrimmSpeed, on an 08-14 hatch) (0:40–1:11)

  6. Unbolt from the downpipe

    • Remove the two bolts joining the downpipe to the mid-pipe.
    Watch this step (1:11–1:36)

  7. Free the hangers

    • Pry each hanger bracket out of its rubber with pliers.
    Watch this step (1:36–2:27)

  8. Fit new hangers

    • Swap in the new exhaust hangers if your kit has them.
    Watch this step (2:27–4:05)

  9. Fit the intermediate pipe

    • Hang the pipe and bolt it to the muffler section with a new gasket.
    Watch this step (4:05–4:55)

  10. Fit the mid-pipe

    • Line up the mid-pipe, then bolt it to the intermediate pipe and downpipe with new gaskets.
    Watch this step (4:55–5:50)

  11. Unbolt the mufflers

    • Remove the two 14mm bolts and pull the muffler off its hangers.
    Watch this step (COBB, on a 2011 WRX) (0:22–1:30)

  12. Remove the pipe

    • Take the pipe off its hanger.
    Watch this step (1:30–1:44)

  13. Fit the new pipes

    • Put on the gaskets and bolts supplied with your exhaust.
    Watch this step (1:44–2:48)

  14. Fit the new mufflers

    • Lube the hanger holes, push the muffler on and fit the gasket.
    Watch this step (2:48–3:58)

  15. Line it up

    • Move the muffler on its hangers until it sits straight, then tighten.
    Watch this step (3:58–4:41)

  16. Remove the old exhaust

    • Undo the flanges and slide it off its hangers.
    Watch this step (on a 2012 STI) (6:16–11:41)

  17. Fit the new exhaust

    • Hang the new pipes and bolt them loosely.
    Watch this step (11:41–14:16)

  18. Change the gaskets

    • Use new gaskets at each joint.
    Watch this step (14:16–17:39)

  19. Finish the assembly

    • Line up the tips and tighten everything.
    Watch this step (17:39–21:57)

  20. Remove the stock exhaust

    • Undo the flange bolts and slide everything off its hangers.
    Watch this step (1A Auto, on a 2016 WRX) (0:00–5:41)

  21. Prepare the new parts

    • Lay the new exhaust out and fit the gaskets.
    Watch this step (5:41–7:03)

  22. Fit the new exhaust

    • Hang the pipes and bolt them loosely.
    Watch this step (7:03–12:52)

  23. Tighten and clean

    • Tighten everything and wipe off fingerprints so they don't burn in.
    Watch this step (12:52–16:07)

  24. Remove the mufflers

    • Undo the flange bolts and pull the mufflers off their hangers.
    Watch this step (Boost & Shutter, on a 2020 STI) (0:33–1:56)

  25. Remove the rear pipe

    • Unbolt the pipe from the downpipe and take it down.
    Watch this step (1:56–3:03)

  26. Fit the new pipe

    • Hang the new pipe with a new gasket.
    Watch this step (3:03–3:40)

  27. Prepare the mufflers

    • Fit any adapter your exhaust needs and hang the mufflers.
    Watch this step (3:40–5:11)

  28. Line up and torque

    • Line up the tips, then tighten everything.
    Watch this step (5:11–8:05)

  29. Remove the stock exhaust

    • Undo the flanges and slide it off its hangers.
    Watch this step (Oakos Automotive, on a 2022+ WRX) (2:31–5:15)

  30. Fit the new exhaust

    • Hang the COBB pipes and bolt them up with the new gaskets.
    Watch this step (5:15–9:28)

  31. Adjust the tips

    • Move the tips until they're even in the bumper, then tighten.
    Watch this step (9:28–11:23)

How to know it worked

Did this guide work for you?

Safety first

  • Park on flat ground, set the parking brake and chock the wheels.
  • Never get under a car held up only by a jack. Use jack stands.
  • Let the engine and exhaust cool first.
  • Disconnect the battery before unplugging electrical parts.
  • Wear safety glasses.
  • If something doesn't match your car, stop and ask a shop.

Follow your part's instructions and your service manual's torque specs.