Subaru v400 Map Updates and New ROM Support

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V400 Subaru WRX, STI, Legacy, Outback, and Forester Off The Shelf Maps

All Subaru Accessports are eligible for a firmware update as a part of this release.  New off the shelf maps for most supported EJ-powered Subarus and the addition of new ROM support for newer vehicles round out notable changes.  At the core of this update for COBB’s Subaru platform are updated v400 Off The Shelf (OTS) Maps for the following vehicles.

  • 2002-2014 WRX (MT & AT)
  • 2004-2018 WRX STI
  • 2018 STI Type RA
  • 2019 STI S209
  • 2004-2013 Forester XT
  • 2005-2012 Legacy GT, Spec B / Outback XT

These v400 map files have received updates to better align with COBB’s vision of providing turn-key upgrade solutions while staying true to our mission statement.  We take the role of being good stewards of the environment and our customers’ safety seriously.  The COBB team will continue to be a leader in the industry by developing and delivering responsible tuning solutions across all of our supported platforms.  Previous iterations of our Subaru OTS Maps contained disabled DTCs and toggles that were not necessary for vehicles to run properly while being used as intended with our Stage Power Packages.  With the introduction of v400 map files we have re-enabled all superfluous trouble codes, including those related to catalytic converter efficiency.  When used in conjunction with our newly re-worked GESi catted downpipes and Stage Power Packages, users can expect DTC-free operation of their vehicle aside from an actual mechanical fault.

v400 Map Files can be downloaded from cobbtuning.com/maps and are included in Accessport Firmware v1.7.4.0-17431 or newer for all Subaru Accessports.

Notable exclusions from the included vehicles in this update are all 2015-2020 WRX (6MT & CVT) as well as the 2019-2020 WRX STI.  We are working through production of updated J-Pipes for the WRXs that will include our proprietary co-developed GESi catalytic converter, once those are available for purchase associated map files will receive the same updates.  The 2019-2020 WRX STI will require a unique downpipe that is currently in development.

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If you haven’t been following along with our Downpipe Updates, we’ve here’s a brief rundown of improvements made to downpipes for most supported EJ-powered Subarus.

Subaru GESi Catted 3″ Downpipe STI 2008-2018, WRX 2008-2014, FXT 2009-2013

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The COBB Tuning GESi Catted 3″ Downpipe begins with a CAD designed cast bellmouth that smoothly blends air exiting the turbocharger’s turbine housing. Minimizing turbulence when exhaust gasses from the wastegate join into those flowing through the turbine helps to prevent excessive back-pressure. The cast housing is capped off with a COBB logo and auxiliary O2 bung for those wanting to install a wideband sensor early in the exhaust path.

A welded bracket utilizes the factory hard mount near the transmission reducing stress on the turbocharger mounting bolts and studs.

Corrosion resistant and mandrel bent 3″ 304 Stainless Steel tubing carries exhaust gasses down stream into a COBB-exclusive GESi 300 cell high flow catalytic converter. A second O2 bung is located directly after the catalytic converter and is to be used by the OEM Rear O2 sensor.

A CAD designed, cast 304 stainless steel, flange finishes off the tail section of the downpipe. The reinforced cast flange is less susceptible to warp during assembly and for those of you installing with the strength of The Hulk. A stainless adapter flange and included MLS gasket allows direct fit with the factory exhaust or COBB Cat-Back Exhaust utilizing the OEM donut gasket. Included COBB proprietary shoulder nuts allow for installation of the factory spring bolts without fuss.


Subaru GESi Catted 3″ Downpipe 2002-2007 WRX/STI, 2004-2008 Forester XT

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The COBB Tuning GESi Catted 3″ Downpipe is one of the premier modifications most owners look to upgrade on their turbocharged Subaru. By increasing exhaust flow coming out of the turbocharger, an upgraded downpipe provides substantial power gains when combined with appropriate tuning.

The COBB Tuning GESi Catted 3″ Downpipe begins with a CAD designed cast bellmouth that smoothly blends air exiting the turbocharger’s turbine housing. Minimizing turbulence when exhaust gasses from the wastegate join into those flowing through the turbine helps to prevent excessive back-pressure. The cast housing is capped off with a COBB logo and auxiliary O2 bung for those wanting to install a wideband sensor early in the exhaust path.

A welded bracket utilizes the factory hard mount near the transmission reducing stress on the turbocharger mounting bolts and studs.

Corrosion resistant and mandrel bent 3″ 304 Stainless Steel tubing carries exhaust gasses down stream into a COBB-exclusive GESi 300 cell high flow catalytic converter. A second O2 bung is located directly after the catalytic converter and is to be used by the OEM Rear O2 sensor.

A CAD designed, cast 304 stainless steel, flange finishes off the tail section of the downpipe. The reinforced cast flange is less susceptible to warp during assembly and for those of you installing with the strength of Hulk. A stainless adapter flange and included MLS gasket allows direct fit with the factory exhaust or COBB Cat-Back Exhaust utilizing the OEM donut gasket. Included COBB proprietary shoulder nuts allow installation of the factory spring bolts without fuss.


Subaru GESi Catted 3″ Downpipe 2005-2009 Legacy GT / Outback XT Automatic

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The COBB Tuning GESi Catted 3″ Downpipe is one of the premier modifications most owners look to upgrade on their turbocharged Subaru. By increasing exhaust flow coming out of the turbocharger, an upgraded downpipe provides substantial power gains when combined with appropriate tuning.

The COBB Tuning GESi Catted 3″ Downpipe begins with a CAD designed cast bellmouth that smoothly blends air exiting the turbocharger’s turbine housing. Minimizing turbulence when exhaust gasses from the wastegate join into those flowing through the turbine helps to prevent excessive back-pressure. The cast housing is capped off with a COBB logo and auxiliary O2 bung for those wanting to install a wideband sensor early in the exhaust path.

A welded bracket utilizes the factory hard mount near the transmission reducing stress on the turbocharger mounting bolts and studs.

Corrosion resistant and mandrel bent 3″ 304 Stainless Steel tubing carries exhaust gasses down stream into a COBB-exclusive GESi 300 cell high flow catalytic converter. A second O2 bung is located directly after the catalytic converter and is to be used by the OEM Rear O2 sensor.

A CAD designed, cast 304 stainless steel, flange finishes off the tail section of the downpipe. The reinforced cast flange is less susceptible to warp during assembly and for those of you installing with the strength of Hulk. A stainless adapter flange and included MLS gasket allows direct fit with the factory exhaust or COBB Cat-Back Exhaust utilizing the OEM donut gasket. Included COBB proprietary shoulder nuts allow installation of the factory spring bolts without fuss.


Other Updates

Additional ROM support:

  • 2017 USDM WRX 6MT
  • 2018 USDM WRX 6MT
  • 2019 USDM WRX 6MT
  • 2020 USDM WRX 6MT
  • 2021 USDM Ascent

Calibration Data Update:

Minor Map update for 2019 STI S209 to improve extreme cold-start conditions.

  • Stage1 93 v357 Boost Select


30 responses to “Subaru v400 Map Updates and New ROM Support”

    • Nothing to update at the moment, unfortunately. We’re continuing with on-car testing and hope to have some more information soon!

      Marshall@COBB

  1. Hi Marshall, should I stick with V331 map for MY13 WRX with an old Cobb catted downpipe (bought in 2013, that wasn’t the new GESi cat, right?)? Or go with the V400? Thoughts/recommendations? Many thanks in advance Marshall.

    • Hey there! You may actually have a couple of options – I’ll ask one of our Customer Service Reps to reach out to you directly so you’ll be able to decide what is best for your situation.

      Marshall@COBB

  2. When will you guys release a firmware update to make the 2021 WRX compatible with the accessport?

    • Hi Antonio, efforts to support the 2021 WRX 6MT are well under way. We hope to be able to release support by early June.

      Marshall@COBB

  3. Hey Marhsall, is there any news regarding the release of the new v400 maps for people that has purchased the new 2020 WRX GESi Jpipe? Thoughts/Recommendations on how to proceed regarding tune and installation to be able to drive to a pro-tune? Thank you in advance Marshall.

    • Hi Joey! We’ve actually made GESi-catted J-Pipe compatible v400 maps available for 2015-2020 WRXs. They won’t be available in firmware, so you’ll need to head over to the Maps Section of our website (https://www.cobbtuning.com/maps/) and download the specific file you’re looking for.

      Marshall@COBB

  4. Hey mate is there any news about ADM support, hope its coming along quite good and will be rolled out soon, cheers.

  5. Hi there I live in the UK does anyone no if I can get a cobb accessport to support the the UK ecu thanks matt

    • Hi Al,

      Yes. The v400 maps are still the current version. They are available for download on the website and come in your Accessport’s firmware if on the current version.

      Kyle@COBB

  6. Is there an estimate for when catted J-pipes will be available for the 2015-2018 WRX? It seems nobody on the market has gotten any through the CARB process yet despite the improved Gen2 GESI cats.

  7. Is there a Stage 2 map for 02 wrx with aftermarket CAI and aftermarket TBE..only saw stage 1 either way let me know

    • Hey there, we no longer offer Stage 2 OTS files. Cars with upgraded downpipes will need to be custom tuned.

      Marshall@COBB

  8. Hi Marshall. I can’t seem to find the v400 stage 2 map for my 2017 wrx. I bought the latest jpipe catted with gesi.

  9. What about all the flex fuel stuff I paid for? It can’t come along for the next round of upgrades. Is cobb working on a solution?

    • Hi Richard,

      Yes. We are working on a legal solution that will ideally be compatible with what you already have. The end result is still TBD though.

      Kyle@COBB

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