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2019 Subaru WRX STI S209 Support

S209 Blog Cover

We are excited to announce that the COBB Accessport and Accesstuner Pro HL software now fully support the 2019 WRX STI S209.

Subaru Accessport V3 (AP3-SUB-004)

accessport_v3_subaru The Accessport is the world’s best selling, most flexible, and easiest to use ECU upgrade solution for your Subaru. Unlock power hidden within the vehicle by replacing conservative factory settings with more aggressive calibrations. Follow our staged upgrade path with pre-loaded Off The Shelf (OTS) maps or use custom mapping for any modification level. It’s the last engine management solution you’ll ever need.

Subaru Accessport V3 (AP3-SUB-004)

Off The Shelf Maps

The COBB OTS Map availability for the S209 is a bit different than our typical WRX or STI assortment. With a limited number of cars available to be used for testing, and based on our findings, the only performance map offered at this time is a Stage 1 OTS map for 93 octane fuel. During investigation and development of this map, our calibration team noted that even utilizing the factory calibration with 93 octane fuel, the S209 exhibited an inconsistent and undesirable amount of knock. As you can see in the graph below, power sometimes suffered significantly on the factory calibration, so we were forced to call it quits before 6400 RPM. We were able to mitigate most of the undesirable activity in the Stage 1 93 map file and carry power out much more consistently up top, but did not attempt to achieve similar results using 91 octane fuel.

Stock vs Stock vs Stage 1

The Red (Run 1) and Green (Run 2) pulls represent power utilizing the factory calibration on two separate days.  The temperature difference was about 40 degrees Fahrenheit (40F vs 80F) between the two days and that difference made a significant impact in overall power.  Power gains as tested were 7-15% for both horsepower and torque.

Non-Performance Map Files

Two additional map files accompany the Stage1 93 performance file for the S209.

  • Stage 0
  • Vehicle Anti-Theft Mode

The Stage 0 map file carries the factory calibration data over for users who may want to retain factory performance level while utilizing other Accessport functionality, such as monitoring live gauges or data logging.  The Vehicle Anti-Theft Mode map file will prevent the engine from being started, thus creating a level of theft deterrence.

Accesstuner Pro HL


For those who are looking to take their S209 beyond the Stage 1 power level, Subaru Accesstuner Pro HL now supports this vehicle with our normal assortment of COBB Custom Features.