Secondary Air Injection Pump Fails on Mercedes-Benz E320

Average mileage: 131,500 (60,000–240,000)
3 model years affected: 1999, 2003, 2004
4 people reported this problem
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Viewing 1 - 3 of 3 problem details
The check engine light illuminated. An OBD reader confirmed a problem with the Secondary Air Injection System. I also noticed a loud roaring type noise for the first two minutes after vehicle starting. The problem was traced to a failed Secondary Air Injection Air Pump. Dealer wanted $1,300 to replace. I sourced a Bosch pump for the application and replaced it myself for around $450.
My yellow engine monitoring light came on, the car was going back to Uk ( from Italy ) for it's annual service. Called mercedes they said it should be ok for trip, car ran beautifully smooth like a new car. But when I arrived at service garage after driving 1000 miles I was told it's the secondary fuel injection pump, part cost £999 :( can these be reconditioned :)