Fitment Information Honda Civic Si (2017, 2018, 2019, 2020, 2021) Emissions Compliance This item does not have a CARB EO Number and does not ship to California or any CARB states. Specs & Features 100% recirculating Higher flow Pressure tested to 75 PSI Easy install No need for re-tune Product Description This high performance recirculating bypass valve is precision machined out of aircraft grade billet aluminum which is far superior to the cheap plastic factory piece. It features an internal brass piston design and is pressure tested to withstand up to 75psi, allowing it to compliment even the most aggressive turbo builds. Spring pre-load determines the pressure differential required across the piston before the BPV opens and releases the pressurized intake charge. Designed to be a replacement for the OEM bypass valve and is available in 4 different colors. No aftermarket tuning required. Will work on stock tune or aftermarket tunes. This piece does not throw any check engine lights, does not cause any turbo lag, and does not make the vehicle stutter between shifts. **For Off-Road Use Only** Many Boomba Racing products are sold for off-road use only. All performance modifications and installations are at the customer’s own risk. Boomba Racing Inc or www.boombaracing.com hold no responsibility either implied or otherwise for mechanical, electrical or other failure when using any aftermarket performance products. Items sold for off-road use only are illegal in many states and provinces and are intended for racing vehicles which may never be used on a public road. By purchasing any aftermarket performance product, the customer takes full responsibility for any use, and/or misuse of the product and agrees that Boomba Racing Inc or www.boombaracing.com holds no responsibility for any consequences, legal, or other, of such use and/or misuse.