Originally Posted by
gedwar1
I can't say with 100% certainty the pumps are the same internally? I just know that my superior Mercedes secondary air pump burned up when the relay stuck closed for about 10 minutes (to its credit, it also had 8 years of service). However, my potentially inferior Audi pump hung in there. When the relay stuck closed, the Audi pump was running for about 15 minutes; hot as a firecracker before I got pulled over in Houston traffic where I could safely unplug the pump; saving its life from an evil relay. After changing the relay my Audi pump runs fine. I was pretty proud of my research and decision to not pay the extra money for a Mercedes or a SRT-6 secondary air pump. I feel like a made the correct choice and got exactly the same pump but like you said there could be differences that I am not aware of. Even if there are subtle differences the Audi pump is a good and proven option for the less purist among us. I am only trying to offer my learning experience as a potential option.
And the knowledge that it works so far is great for those who may want to try your solution. Have you tried to pull any codes to see if anything is listed that doesn't trip a CEL? That would help others (maybe reassure) that it could be worth a try? The cfm/rpm may be different, as well as any number of other things like current draw. I don't know, knowing things like this helps others determine if the part is a replacement (more robust, or not). Just food for thought!