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WRX ECU tune (Accessport)

Your WRX

Pick your year to see what fits.

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

+20–50 whp (est.)
Easy$735–$77030 min
All WRX mods

Why do it

A tuner loads a better map onto the factory computer. It's the single biggest gain on a turbo Subaru and it's what makes the other power mods work.

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

  • Connect a battery charger if you can. A low battery during a flash can cause real problems.
  • Never turn off the car or unplug the Accessport during a flash.
  • Connect a battery charger if you can. A low battery during a flash can cause real problems.
  • Never turn off the car or unplug the Accessport during a flash.
  • Connect a battery charger if you can. A low battery during a flash can cause real problems.
  • Never turn off the car or unplug the Accessport during a flash.
  • Connect a battery charger if you can. A low battery during a flash can cause real problems.
  • Never turn off the car or unplug the Accessport during a flash.

Steps

  1. Get ready

    • Charge the battery and have the Accessport and cable ready.
    Watch this step (on a Bugeye WRX, with the older V2) (0:00–1:00)

  2. Connect it

    • Plug the Accessport into the port under the dash.
    Watch this step (1:00–2:26)

  3. Flash the ECU

    • Follow the screen and let the flash finish.
    Watch this step (2:26–3:32)

  4. Check the tune

    • Start the car and check the map loaded.
    Watch this step (3:32–4:43)

  5. Prepare the tuner

    • Update it and pick your map.
    Watch this step (Subaru Shakedown, on an 08-14 WRX) (0:00–1:34)

  6. Flash the ECU

    • Plug in, follow the screen and let it finish.
    Watch this step (1:34–4:06)

  7. Mount it

    • Fit a mount where you can see it, if you want one.
    Watch this step (4:06–6:53)

  8. Install the software

    • Install Accessport Manager from COBB's site.
    Watch this step (MAPerformance, on a 2015+ WRX/STI) (0:46–1:34)

  9. Update the Accessport

    • Plug it into your computer and click connect.
    Watch this step (1:34–2:31)

  10. Charge the battery

    • Hook the car up to a battery charger.
    Watch this step (2:31–2:55)

  11. Plug in and install

    • Plug into the OBD2 port and follow the screen to install to the car.
    Watch this step (2:55–4:50)

  12. See what's in the box

    • Check you have the Accessport and cable.
    Watch this step (MAPerformance, on a 2022 WRX) (0:30–2:30)

  13. Install it

    • Follow the steps to update and flash your car.
    Watch this step (2:30–6:05)

  14. Mount it

    • Fit a mount where you can see it, if you want one.
    Watch this step (8:35–9:54)

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.