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P0041

P0041

Oxygen sensors behind catalytic converter interchanged - signal implausible

Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Relatively long drive in various operating states
- Short test "Sensor replacement diagnosis after cat"

Possible cause of fault
- Oxygen sensors behind catalytic converter interchanged (i.e. the sensor for bank 1 is inserted in the exhaust assembly for bank 2 and vice versa)

Affected pins
-

Diagnosis/troubleshooting

NOTE: This fault only occurs in relation to V6 engines.

WARNING: Always observe the notes on possible dangers, the warning and caution notes as well as the general instructions in the introduction.

NOTE: Do not use contact spray on the oxygen sensor plug connections, as this may cause irreparable damage to the wiring (blocking the reference air channels).

NOTE: Do not confuse oxygen sensor ahead of catalytic converter and oxygen sensor behind catalytic converter as this will cause implausible fault entries.

Distinguishing feature of both sensors:

Oxygen sensor ahead of catalytic converter (LSU) has a six-pin connector







Oxygen sensor behind catalytic converter (LSF) has a four-pin connector






NOTE:
- During diagnostic procedures, the mixture on one bank is enriched, while the mixture on the other bank is more lean.
- This fault is detected if the oxygen sensor behind the catalytic converter indicates a leaner mixture on the enriched bank, and if the oxygen sensor behind the catalytic converter indicates a more enriched mixture on the lean bank.






Arrangement of oxygen sensors for the V6 engine