Full recirculating BOV. The Plumb Back system recirculates all excess pressure back into the intake system. Great for enthusiasts who do not want to be noticed but want the performance and reliability benefits of a quality BOV.

Full recirculating BOV. The Plumb Back system recirculates all excess pressure back into the intake system. Great for enthusiasts not wanting to be noticed but wanting the performance and reliability benefits of a quality BOV.

Note: that this will require two valves for twin-turbo applications, such as the Audi S4 2.7L (B5) 97-01.

What's Included:

• Turbosmart 97-06 Audi A4 1.8T 20V / 99-03 Audi S3 1.8T 20V Kompact Plumb Back Diverter Valve (25mm)

Vehicle Fitment: