E36 Secondary Air Pump

E36- Have OBDII codes p1423, 1421 and 0420. Planning on replacing the faulty o2 sensor this weekend and take a look at the Secondary Air Intake Valve. Before I replace the pump itself, does anyone have any
suggestions on how to determine if in fact the pump is still functioning? Or is it almost a given that, based on the three codes above, the pump is dead?
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have had the same problem on my E36, except I didn't have the 0420 code. No it's not "a given" that the pump is dead.
When the engine is cold, and you start-it, the pump makes a noise like a vacuum cleaner for about 90 seconds until the engine warms up. It's also not too difficult to remove the pump and run it directly from the battery to test it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.