One of the weakest parts on any chipped 2.0T FSI and 2.5T engine is the diverter valve. The factory diaphragm style valve is prone to cracking under high boost pressure, which creates a massive boost leak, resulting in loss of HP. This OEM/OES valve upgrade from the new TSI engines feature an upgraded piston type design modeled after the more expensive aftermarket units. This is a must have upgrade for any chipped 2.0T FSI with the factory diaphragm style valve.