Puzzeled On P0492 Code

Need some Bimmer expert input

I have an intermittent Increased Emissions and code P0492, Secondary Air Pump SES.

The SES illuminates at least twice monthly on the same drive. The airpump always is on for the first 60 to 90 seconds. The SES light comes on after 10 to 12 minutes of driving and usually at the same spot in the drive (when it happens).

I have concluded that the airpump cycles ok that the SES comes on when way beyond the pump cycle and with my Actron I see no O2 sensor errors.

What causes the secondary airpump SES when the airpump is off ( Atmosphere mode) and upstir has already ended????

Originally Posted by Hogie

Need some Bimmer expert input

I have an intermittent Increased Emissions and code P0492, Secondary Air Pump SES.

The SES illuminates at least twice monthly on the same drive. The airpump always is on for the first 60 to 90 seconds. The SES light comes on after 10 to 12 minutes of driving and usually at the same spot in the drive (when it happens).

I have concluded that the airpump cycles ok that the SES comes on when way beyond the pump cycle and with my Actron I see no O2 sensor errors.

What causes the secondary airpump SES when the airpump is off ( Atmosphere mode) and upstir has already ended????

I'm guessing either clogged secondary air ports or pre-Cat O2 sensors. See the attached links.

http://blog.bavauto.com/9468/bmw-n62...secondary-air/

http://forums.bimmerforums.com/forum....php?t=1254257

Does any body know how to change o2 sensor on 2009 X6. Please help