Need some help, getting Secondary air pump codes 80 and 81 on e39 540i.
1. CEL was cleared twice, codes keep coming back.
2. When engine start, secondary air pump starts really loud for about 2 minutes, shuts off and engine runs smooth.
3. Codes are:
50  function secondary-air system, bank 1
51  function, secondary-air system, bank 2
Since the pump seems to be running, and both banks are affected it sounds like a check valve or sensor problem, or the hoses are clogged. Any ideas?
I need to pass emissions soon.