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Cobb NextGen STG 2 NextGen STG 2 + Flex Fuel Package Upgrade – 08-21 STI

Cobb NextGen STG 2 NextGen STG 2 + Flex Fuel Package Upgrade – 08-21 STI


This package is intended to be added to our 50-state legal NexGen Stage 2 Power Package. It includes both our NexGen Ethanol Content Sensor Kit and Fuel Pressure Sensor Kit, required for use with the supporting NexGen Stage 2+FlexFuel Off The Shelf Maps.


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This plug and play NexGen Ethanol Sensor Kit is the heart of our NexGen Flex Fuel product offering. It consists of an ethanol content sensor with mounting bracket, fuel lines to be used with the COBB Fuel Lines, a NexGen Flex Fuel module, and a plug-and-play wiring harness to bring it all together.

The OE quality ethanol content sensor is secured to a bespoke powder coated aluminum bracket. Fuel is then fed to and from the sensor with pre-made fuel line with OE quick disconnect. A billet adapter is included to allow for seamless integration with the COBB Fuel Rail Line Kit.

The NexGen Flex Fuel Module is mounted to the passenger side strut tower and handles all of the data processing before sending ethanol content to the ECU to be used by an Accessport-delivered NexGen Flex Fuel calibration.

Tying everything together is a custom, easy to install, plug-and-play wiring harness. Utilizing OE quality wiring and connectors makes adding NexGen Flex Fuel on your supported Subaru both quick and reliable.

The Cobb Fuel Pressure Sensor Kit is a plug and play solution enabling users to monitor Fuel Pressure on a Custom Accessport monitor. The Fuel Pressure Sensor Kit uses OEM quality connectors, making fit and finish second to none. Utilizing existing factory inputs, this kit will allow users to easily monitor Fuel Pressure on supported Subaru vehicles.


Subaru NexGen Flex Fuel Ethanol Sensor Kit STI 2008-2021

  • NexGen Flex Fuel Module
  • Plug and Play Wiring Harness
  • Ethanol Content Sensor with Bracket

Subaru Fuel Pressure Sensor Kit (5 Pin) STI 2008-2021

  • OEM Quality Connectors
  • Billet Aluminum Sensor Adapter
  • 0-100 PSI Sensor
  • 1/8″ NPT
  • Required for COBB NexGen Flex Fuel OTS Maps


This part is legal under the provisions of EPA’s Anti-Tampering Policy. COBB Tuning has established a reasonable basis (testing results) to verify that this product allows the vehicle to operate within legal emissions standards and is therefore legal to be sold for on-street use in all states that accept the legal provisions of the Clean Air Act and EPA’s Anti-Tampering Policy. NOT LEGAL FOR SALE OR USE IN CALIFORNIA ON ANY EMISSION CONTROLLED MOTOR VEHICLE.

Testing with the California Air Resources Board, in order to achieve 50-state compliance, is pending. Once testing is complete with California, and an EO number is issued, this product will be updated to 50-state legal status.


  • 2008-2021 STI


Installation Guide

Flex Fuel Install Guide

Fuel Pressure Sensor Install Guide