12-7-2023 Update-

Cobb has rereleased flex fuel kits for the 2008-2021 STI and the 2015-2021 WRX is rumored to be released next. Those kits can be found here. 

7-11-2022 update:

A new style of flex fuel is available from Delicious Tuning that works with Cobb’s Green Speed updates. More info can be found in our blog post here.

📣📣Flex Fuel Update📣📣

We have had a lot of inquiries over the last 24hrs about Cobb’s recent update.

***On May 2, 2022, our tuning program gets automatically updated by Cobb. After that anyone that has been previously flex fuel tuned or had any codes disabled when tuned, we will not be able to update your tune. After the update when we save the tune it will automatically revert back to stock, the tables for flex/fuel pressure sensor and re-enable all the check engine lights.***

As much as this all sucks it needs to be done so you can keep modifying your cars. We have to start doing this in a way that works with the current laws or there may be a day we won’t be able to put any aftermarket parts on our cars at all. Nobody wants that.

What does Cobb’s Project Green Speed update mean for you?

If you are currently tuned on flex fuel with an Accessport you have absolutely nothing to worry about. You are not going to lose your tune and it won’t be automatically updated and remove flex fuel. If you need any updates or decide to add more parts, that is where you will run into trouble. The best advice I can give at the moment is to just leave your car how it is and enjoy it.

On April 18th, Cobb released an update for the pro tuning software that removed the features that allowed us to tune flex fuel, add custom sensors like fuel/oil pressure, and disable any DTC (Diagnostic Trouble Codes / Check Engine Lights). This was done because utilizing these custom sensors was overriding the signals from the rear O2 and TGV’s. Even though it was done in a way that still allowed the TGV’s to still be fully functional, some check engine lights had to be turned off, thus tampering with how the emissions system functions. Cobb says they are working on updating how flex fuel works so it can be fully emissions compliant.

There is unfortunately no ETA on when that will be available. While we can no longer tune flex fuel, that doesn’t mean you can’t still run E85, upgraded turbos, upgraded fuel injectors, and downpipes. Companies like GrimmSpeed are working on emissions compliant exhausts that won’t throw any check engine lights. They have already released the 2015+ WRX J-Pipe and I’m sure the downpipe isn’t far behind. We can still tune your car with an Accessport. We just have to do it in a way that doesn’t remove parts that didn’t add power anyways. Removing TGV gains 5hp, maybe. The rest like EVAP, EGR, air pump gain no power at all. We have been retaining these items for a long time now and the cars we tune still make big power with them installed.

Can you still run E85?

The simple answer is yes. We can tune E85 like we did before flex fuel was a thing. Flex fuel for Subaru has only been around since 2015. People have been running E85 long before that. Instead of flex you will have dual tunes. You will get a pump gas tune along with 2 E85 tunes, a summer and winter blend to account for the changing ethanol content. These will make the SAME POWER as a flex tune, you just have to flash a new map a few times a year.

To sum up:

  • We CAN still tune cars with Accessports
  • We can NOT disable any check engine lights, no power was gained from this anyways.
  • We CAN and still will tune cars on E85
  • We can NOT tune flex fuel anymore, straight E85 tunes make the same power as flex tunes.
  • We CAN still tune flex fuel on opensource for the 2002-2005 WRX and EVO X.
  • We CAN still tune open source and have support for 2004-2020 STI, 2002-2014 WRX

More information can be found on Cobb’s latest Green Speed Update here