Forge Motorsport Recirculation Valve for Audi S4 B9 and Audi S5 B9. We recommend servicing your valve every 3 years, or 20,000 miles, whichever comes sooner. Forge Motorsport Recirculating valve for the Audi S4 B9 and Audi S5 B9. This product is a solenoid operated valve that integrates seamlessly with the OEM electronics resulting in absolutely no fault codes, no check engine lights, and no detriment to the performance of the vehicle in any way. These valves, designed and manufactured by Forge are engineered to remedy the failure issues experienced with the OEM solenoid valves when the diaphragm or plastic piston fails which would effectively result in a boost leak.Forge valves use full billet alloy construction with a piston based internal design that provides significantly improved reliability, lightning fast response and will withstand additional tuning upgrades. An atmospheric valve replacement is also available. In The Box: 1 x FMDV13 Valve 1 x Wiring Harness 1 x Solenoid, Bracket, and Screws 1 x Blue Spring (Uprated) 10 x Cable Ties 1 x 2000mm Length of 4mm Vac Hose 1 x Instructions 1 x Forge Keyring and Sticker. Mods4U is a small family run business who have been working within the modified car parts scene for some time. We are a small business and as such there may be occasions when we are unable to fulfil the order due to issue out of our control so please bear with us!