I have a 2000 Passat 1.8t auto that runs rough with a P0411. When I checked with a local dealer-they recommended checking for water at the secondary air pump; water was present. After confirming that, they recommended replacing the combination valve along with the secondary air pump. I checked the integrity of the hoses going to the combination (EGR/AIR) valve and they all look OK. Does anyone have any further recommendations-or should I be comfortable with just replacing these two parts? Or should the dealer be the one to work on it-though their reputation is poor, and the price quite the opposite. Thanks for any help!

If water has been in both then it might be best to replace them (both are prone to failure). VW prices the pump high, there are some sources online.