This valve is for VW and Audi vehicles equipped with the 2.0T FSI or TFSI engines that have electronically controlled bypass / diverter valves. It is recommended for any vehicle where the boost pressure has been increased by an ECU software upgrade, or if you are looking for a more reliable solution to the factory diaphragm valve. Forge Motorsports diverter valve and installation kit replace the original unit with a pressure/vacuum operated piston valve that still functions like the oem unit. With this kit ECU control over the valve is retained, valve response time is improved, and you will not get any fault codes, check engine lights, or adverse effects. Istall is simple and easy with the included instructions and all neccesary components are included. A unique feature of this kit is the included Boost Tap. It connects to your intake manfold and serves not only as a boost reference to the valve but can be used in the installation of a boost gauge or a water / methanol injection kit. This kit is supplied with an additional uprated spring (coded Yellow) that may be required if the vehicle has had a significant boost increase.