When the secondary air injection pump on your VW begins to fail, you get a loud whine on a cold start when it turns on. If you look at it, you can often see the aluminum rivets coming apart. When this fails, you can get a DTC. The flow will be too low to warm the catalytic converter.
To clear all those DTCs and get your vehicle running properly again, the only answer is replacement. This quality unit from ECS Tuning is the perfect replacement for your faulty or failing pump. Bolts right up in the stock location and gives you stock performance.