OBDMID $74 (116): Secondary Air Injection (AIR) System 4 (Bank 4)

WARNING: This page is about a different car, the 2009 Audi S8, 2008 Audi S8, and 2007 Audi S8. However, it is still accessible from the selected car via links, so may be relevant.

Connect the scan tool.
Start the engine and let run at idle speed.
Select "Mode 6: Check test the results of components that are not continuously monitored".

Select "OBDMID 116 ($74)".

Select the desired "Test-ID".
Check specified values at idle.

Test-ID (TID) (Hex-ID)	DTC	Component or System	Min.	Max.	Additional Information
128 ($80)	P1498	Function Check.	0.0468	---	Refer to DTC P1498 in the DTC table.

If any of the components or systems fail to meet the specified values, refer to Diagnostic "Mode 03: Interrogating Fault Memory" to check for stored DTCs or the corresponding diagnostic repair procedure.
Switch the ignition off.
End of diagnosis.