Cobb Subaru 08-21 STI (Incl. 2018 Type RA) Fuel Pressure Sensor Kit - 315650

The COBB Fuel Pressure Sensor Kit (Part #315650) is a purpose-built fuel pressure monitoring solution designed specifically for the 2008–2021 Subaru WRX STI, including the 2018 Type RA limited edition. Engineered to work seamlessly with the COBB Accessport, this plug-and-play kit gives STI owners real-time visibility into fuel pressure — critical data for any tuned or modified EJ257-powered build. Whether you're chasing a proper tune on pump gas or building toward an E85 flex-fuel setup, knowing what your fuel system is doing under load is no longer guesswork.

Key Features & Benefits

• Plug-and-Play Integration: Designed to connect directly with the COBB Accessport ecosystem, allowing users to create a custom Accessport monitor displaying live fuel pressure data — no standalone gauge or extra display hardware required.
• Purpose-Built for the STI Fuel System: Engineered specifically for the 2008–2021 Subaru STI, so fitment and connector compatibility are built in — not adapted from a generic sensor.
• Accurate Fuel Pressure Monitoring: Delivers reliable fuel pressure readings that help tuners and drivers identify fuel delivery issues, pressure drop under boost, or lean conditions before they become engine-threatening problems.
• Complements Other COBB Fuel System Components: Pairs naturally with COBB's own fuel pressure regulators and flex fuel ethanol sensor kits, making it a logical addition to a staged COBB fuel system build.
• CARB Compliant: Carries CARB EO number D-660-13, supporting use in California-registered vehicles where emissions compliance matters.

Specifications

• Part Number: 315650
• SKU: COBB315650
• UPC: 700424674527
• CARB EO: D-660-13
• Connector: 5-Pin (as referenced in manufacturer product title)
• Compatible Monitor: COBB Accessport (custom monitor channel)

Fitment

This fuel pressure sensor kit is confirmed to fit the following vehicles:

• 2008–2021 Subaru WRX STI (all trims)
• 2018 Subaru STI Type RA (specifically included)
• 2021 Subaru STI Final Edition (covered within the 2008–2021 range)

If you are unsure whether this kit is compatible with your specific build — particularly if you've already made modifications to the fuel rail or fuel delivery system — contact the ThreePiece.us fitment team before ordering. This kit is designed around the stock STI fuel system architecture for the years listed above.

What's in the Box

This kit includes the components necessary for plug-and-play fuel pressure monitoring on the supported Subaru STI platforms. For a complete list of included hardware, contact our team or refer to COBB's installation documentation for part number 315650.

Why Buy from ThreePiece.us

• Free Shipping: Every order ships free — no minimum required, no hidden fees at checkout.
• Affirm Financing: Break your purchase into manageable payments with Affirm financing, available at checkout. Lease-to-own options are also available.
• Expert Fitment Support: Not sure if this sensor kit works with your current fuel system setup? Our team has served 10,000+ customers and can help verify compatibility before you buy. Reach us at 813-535-5801 or via the contact form.
• Regularly Stocked: The COBB 315650 is a regularly stocked product at ThreePiece.us, so you're not waiting on special-order lead times.
• Genuine Products: We carry 100% authentic COBB parts — what you see is what you get, with the full manufacturer part number and UPC to confirm.

Frequently Asked Questions

Q: Which Subaru STI years does the COBB 315650 fit?
A: This fuel pressure sensor kit is designed for the 2008 through 2021 Subaru WRX STI, including the 2018 Type RA. If your STI falls within that model year range, this kit is the correct application.

Q: Do I need a COBB Accessport to use this sensor kit?
A: Yes. The COBB Fuel Pressure Sensor Kit is designed to enable fuel pressure monitoring through a custom Accessport monitor. The Accessport is the display and data interface for the sensor readings, so it is a required companion device for this kit to function as intended.

Q: Is this kit legal for use in California?
A: Yes. The COBB 315650 carries CARB EO number D-660-13, indicating it has received California Air Resources Board approval for use on supported vehicles.

Q: Can I combine this sensor kit with other COBB fuel system parts?
A: The COBB 315650 is designed to work within the broader COBB fuel system ecosystem. Compatible companion products include COBB's fuel pressure regulators and NexGen flex fuel ethanol sensor kits for the STI. If you're building out a more complete fuel system upgrade, our team can help you identify which COBB components work together for your specific goals.