Cobb tuned Subaru WRX after the Project Green Speed update

Cobb Project Green Speed: What It Means For WRX Tuning

Under pressure from the EPA (Environmental Protection Agency), and CARB (California Air Resources Board), Cobb Tuning has had to make some changes to how their AccessPort and AccessTuner software work.

Does this mean the end of Subaru WRX tuning and modifying? Fortunately, the answer is no. However, certain modifications have now been limited, and tuners won't be able to create new tunes for certain parts.

We've got everything you need to know about the Cobb Green Speed Update and how it affects the ability to tune your car.

What Is The Cobb Green Speed Update?

New regulations have forced Cobb's hand, as well as some other manufacturers in the aftermarket industry to making some changes to their product lineup.

With the new software update to Cobb's AccessTuner software, tuners are no longer able to disable codes related to emissions equipment with a custom tune. This means many parts, such as existing Flex Fuel kits, many downpipes, TGV deletes, secondary air pump deletes, and others can't be installed.

Cobb has also made a big effort to get existing parts through the CARB EO approval process to make them smog legal in California. They've currently received 88 executive orders from CARB, and have many more applications for other parts working their way through the approval process.

See Cobb's statement on the update:

"Work on our Green Speed mission has been ongoing behind the scenes for multiple years, and the product of that work is now coming to light.  We take the role of being good stewards of the environment as well as our customers’ safety seriously.  As we continue to put effort towards being a leader in the aftermarket industry by developing and delivering responsible hard parts, packages, and tuning solutions across all of our supported platforms, you are going to see some changes to calibration (OTS Maps) availability and upgrade path progression on some of our platforms."

Does the Cobb AccessPort Still Work?

Yes, the AccessPort still works. No changes have been made to the Access Port itself, only the AccessTuner software. If you have an existing tune for deleted emissions equipment, you'll still be able flash it, even if you update your AccessPort's firmware.

However, if you need to make any changes, you'll need to reinstall any emissions equipment, since tuners won't be able to save a new file with the associated codes disabled.

Can I Still Install A New Downpipe?

Yes, you can still have an aftermarket downpipe. However, many of the downpipes on the market can no longer be tuned for. The aftermarket industry has responded by creating new GESI downpipes, which are compliant with EPA regulations.

If you live in California, you're less lucky. Unfortunately, manufacturers have yet to get a CARB executive order for any downpipes, meaning your car will still fail smog checks.

No matter where you live, you'll only be able to use a catted downpipe. Using a catless downpipe would require disabling emissions related codes, which is no longer possible. Not only do these codes turn on the check engine light, but they throw the car into limp mode.

You can still make great power on the stock downpipe. Cobb has released a new NextGen Stage 2 Power Kit for the WRX, which includes a more free flowing intercooler, charge pipe, intake and boost controller. These parts and the included OTS (off the shelf) tune all have CARB approval, meaning your car will pass smog in California.

Can I Still Use Flex Fuel?

Currently, it's not possible to create a new tune for Flex Fuel on the WRX. This is because all the existing kits require using existing OEM analog inputs on the ECU, and are installed by replacing the TGV position sensor or rear oxygen sensor input. These are both emissions related equipment, so AccessTuner won't allow replacing these inputs.

Cobb claims to be working on a new kit for the WRX. The new kit will use a CAN bus gateway to avoid tapping into existing inputs on the ECU. Some other cars such as the Nissan GT-R already have CAN-based Flex Fuel kits and are unaffected by the Green Speed update.

This new kit has yet to be released, so for the time being, you'll be unable to install an ethanol sensor on the WRX, or update an existing file for one. The only option is to install a standalone ECU instead, or to have separate tunes created for ethanol and regular fuel, and flash them on fly. While this is inconvenient and requires testing ethanol levels and calculating how much E85 to add, this is the only way to run a WRX on ethanol for now.

What changes have been made to AccessTuner?

The AccessPort itself hasn't been changed, just the tool used to create custom tune files, known as AccessTuner. Cobb is forcing this software update for all AccessTuner users as of April 18, 2022, and old versions won't function after that date.

Here's a summary of what's changed according to Cobb.

Disabling DTCs (Diagnostic Trouble Codes)

Codes related to the following equipment can no longer be disabled, since these are all considered to be emissions related equipment. You can still disable other non-emissions related codes.

  • Oxygen (O2) Sensors
  • Exhaust Gas Temperature (EGT) Sensors
  • Three-way Catalysts (TWC)
  • Exhaust Gas Recirculation (EGR) Systems
  • Stratified Warmup
  • Tumble Generator Valves (TGV)
  • Secondary Air Injection
  • Evaporative System

Additionally, modifying the min/max test parameters that determine a pass or fail for OBD readiness can't be modified. For example, you can't change the threshold at which the catalyst passes based on the rear O2 sensor values.

Visual Indicators

When loading an existing tune with deleted emissions codes, this will be indicted with the toggles and codes greyed out and disabled. Restricted tables will also be greyed out with a lock icon, and AccessTuner will not allow saving the file until these features have been returned to stock. With a new map, any restricted feature will not be visible. 

Alternatives To the Cobb AccessPort

Depending on which model year your WRX is, there may be some alternatives to Cobb's tuning solutions.

For years prior to 2015, opensource tuning is an option. With a Tactrix OpenPort cable along with the EcuFlash or SubaruEdit software on a laptop, you're able to edit ECU tables just like you can with Cobb's solutions. However, this only works on Subarus with the older EJ25 engine or EJ20 engine, since the software has not been updated for the ECU found in the FA20F.

EcuTek is another company that has reverse engineered the FA20's ECU. Many tuning shops are able to flash your ECU using this alternative, and for now, you may be able to have your car tuned for FlexFuel and other mods. However, the parent company of EcuTek also owns Cobb Tuning, so EcuTek may suffer the same fate as Cobb before long.

A stand alone ECU is another option. Haltek is a popular option, with harnesses available to make replacing the factory ECU simple. With a standalone ECU, you'll have a ton more flexibility, also enabling mods such as controlling additional injectors if you'd like to install a BRZ intake manifold.

Keep in mind, with all of these alternatives, any ECU modification with non approved tunes may cause your car to fail smog checks.

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