COBB Subaru Previous Ethanol Sensor Kit to NexGen Flex Fuel Ethanol Sensor Kit Upgrade (Module + Harness Only) - 2015-2021 Subaru STI

The COBB NexGen Flex Fuel Module + Harness Upgrade Kit is designed for 2015–2021 Subaru STI owners who already have COBB’s previous flex fuel implementation installed and want to upgrade to the NexGen Flex Fuel system without purchasing a new ethanol content sensor.

This kit includes the NexGen Flex Fuel Module, which mounts to the passenger-side strut tower and handles data processing before sending ethanol content information to the ECU for use with an Accessport-delivered NexGen Flex Fuel calibration. It also includes a custom plug-and-play wiring harness that ties your existing ethanol content sensor into the new module using OE-quality connectors and wiring for a clean, reliable install.

Key Features

• Upgrade Path for Existing COBB Flex Fuel Users: Designed for customers already running the previous COBB ethanol sensor implementation.
• Module + Harness Only: Does not include a new ethanol content sensor.
• NexGen Flex Fuel Module: Processes ethanol content data and sends it to the ECU for NexGen flex fuel calibrations.
• Passenger-Side Strut Tower Mounting: Clean, supported mounting location for the module.
• Plug-and-Play Harness: OE-quality wiring and connectors for quick, reliable installation.
• Built for NexGen Stage 2 + Flex Fuel Upgrades: Ideal for transitioning to a NexGen Stage 2 + Flex Fuel power package setup.

Cobb Tuning Official Overview

Why We Like It

This is the right solution for STI owners who already invested in the earlier COBB flex fuel setup and do not want to buy parts they already have. It keeps the upgrade focused, clean, and cost-effective while moving you into the newer NexGen flex fuel ecosystem.

Important Notes

• This kit does not include a new ethanol content sensor.
• Intended only for customers who already have COBB’s previous flex fuel implementation installed.
• Requires a compatible Accessport-delivered NexGen Flex Fuel calibration.

What’s in the Box

• (1) COBB NexGen Flex Fuel Module
• (1) Plug-and-play wiring harness

Installation Notes

For Cobb Tunings officalInstall Instructions please click here.

• NexGen Flex Fuel Module mounts to the passenger-side strut tower.
• Harness is designed to connect your existing ethanol content sensor to the NexGen module.
• Professional installation is recommended if you are unfamiliar with fuel system or tuning hardware integration.
• Reference COBB install instructions before beginning installation.

Emissions

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 emissions controlled motor vehicle.

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

Compatibility & Disclaimers

Designed for 2015–2021 Subaru STI applications only. This is a module and harness upgrade kit and is not a complete flex fuel sensor kit. Always confirm your existing hardware configuration and tuning compatibility before purchase.