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P0491 Diagnostic Trouble Code Discussion for October 2006

Secondary AIR System Insufficient Flow Detected (Bank 1)


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Trouble Ticket Help Requests for DTC P0491
Help Request Posted
1999 BMW 540i 4.4L MIL Lamp on VIN: WBADN6346X
P0491: B1 secondary air system failure. ... on recently, Has DTC P0491, P0492 for B1 and B2 secondary air system failure. Freeze frame 680 RPM 100f, 0MPH, 2.7% load, LTFT 1 +9.4%, LTFT 2 +5.5%, STFT 1 -8.6%, STFT 2 -8.6%. Suspect Probable secondary air pump failure need to know what these codes ...
October 03, 2006
1999 BMW 540i 4.4L MIL Lamp on VIN: WBADN6346X
P0491: B1 secondary air system failure. ... on recently, Has DTC P0491, P0492 for B1 and B2 secondary air system failure. Freeze frame 680 RPM 100f, 0MPH, 2.7% load, LTFT 1 +9.4%, LTFT 2 +5.5%, STFT 1 -8.6%, STFT 2 -8.6%. Suspect Probable secondary air pump failure need to know what these codes ...
October 03, 2006