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COBB LF Bypass Valve 2015-2021 WRX / 2014-2018 Forester XT

SKU 745670
Original price $370.00 - Original price $370.00
Original price
$370.00 - $370.00
Current price $370.00

The C.A.R.B. Certified COBB LF BPV is a compact and lightweight by-pass valve that is capable of holding very high boost pressure without leaking. Its updated design reduces control volume by 30% allowing for extremely fast venting of boost when actuated. Innovative engineering and precision manufacturing result in a compact package able to fit in the confines of a tight engine bay. Due to the low weight of the components, the moving parts in the LF BPV have less inertia and can respond faster than heavier components in other bypass valves. This updated design uses a Banjo-fitting vacuum port which provides 360 degree adjustability of hose routing. This results in a simpler install and less potential leak points than the NPT ports. This new design also includes a piston o-ring seal that is twice the diameter of the old design allowing more seal compression and reduced wear. Adjustability of the spring seat is no longer needed due to the updated spring and seal design which provides a 60% increase in clamping force at peak boost while maintaining similar operation at idle and transient loads.

This part is legal for sale and use on Emissions Controlled Vehicles in all 50 states when used in accordance with the manufacturer's application guide because it has a California Air Resources Board (CARB) Executive Order (EO) number:



Customer Reviews

Based on 9 reviews
it go pshhhhhhhh

super easy install, quality piece and love the noise.


Thank you for taking the time to leave a 5 Star Review! It is fantastic to hear that you are pleased with the COBB LF Bypass Valve and its easy installation process. The satisfying 'pshhhhhhhh' noise is definitely a bonus. We appreciate your support!


Beautiful piece

I have not installed it yet but My first impressions are top notch from Cobb and subimods. The package was well put together. Nice heavy duty by pass valve. You can tell it's well made when you hold it. And of course, subimods is excellent as always and quick shipping. Thank you very much.


Thank you for your 5-Star Review! We are so glad to hear that you are impressed with the quality of the COBB LF Bypass Valve. COBB takes pride in creating products that are not only beautiful but also durable. We hope that you will have a smooth installation process and enjoy the results. It is always a pleasure to work with amazing customers like you. Thank you for choosing COBB and Subimods!


Sebastian Patino
Cobb bypass.

Amazing product super fast shipping, great store in general and have many things to choose from. Also very friendly.
The Cobb bypass sounds amazing if your looking for a swoosh it won’t give the flutter but it’s very loud and worth the money


Thank you for your 5 Star Review and for choosing Subimods for your COBB LF Bypass Valve. We are glad to hear that you are satisfied with our fast shipping and wide selection of products. It is also great to know that you found the Subimods Team friendly and helpful. We are happy that the bypass valve met your expectations and provided an amazing sound. We appreciate your support and hope to continue serving you in the future!


Blake Johnson
2021 WRX Cobb BPV

Great build quality and makes some great noises


Thank you for your 5 Star Review! We are glad to hear that you are enjoying the build quality and noises of our COBB LF Bypass Valve on your 2021 WRX. We strive to provide top-notch products for our customers. If you have any further feedback or questions, please don't hesitate to reach out to us. Happy driving!


Yay! Turbo noises! I love this

Ok, full disclosure, it’s loud. No. Seriously. It’s easily able to be heard over casual music or conversation in the car if you’re 10+ psi or better.

For performance, the noise is irrelevant. So if you want a quicker car, you won’t care. Especially if you want a quicker car with no check engine lights.

Here’s the other piece, taste. If you want that sweet, sweet turbo “pssht” noise, and no change engine lights, here’s a wonderful option.

Personally, I just wanna see more Subies on the road. I love giving the WRX wave, so if you see me out there in the wild, gimme the wave. And if you like turbo noises, give me a sound sample on the streets.


Thank you for your enthusiastic 5 Star Review with added pics of the COBB LF Bypass Valve. It is great to hear that you are enjoying the turbo noises it provides and that it doesn't trigger any check engine lights. Turbo enthusiasts will surely appreciate the 'pssht' sound. Your love for Subies and the WRX wave is a testament to the strong sense of community among Subaru owners. Enjoy your Subie adventures and happy driving!


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