Engine and gearbox (P)
P0041: O2 Sensor Signals Swapped
This code indicates that the signals from the oxygen sensors after the catalytic converters on bank 1 and bank 2 are swapped. This often happens after recent maintenance or sensor replacement.
Checked by a licensed car technician · last reviewed 30 September 2026
Symptoms
- Check engine light on
- Possible decrease in fuel efficiency
- Failed emissions test
Common causes
- Sensors swapped after replacement
- Incorrect wiring connections
- Faulty oxygen sensor
How to check it yourself
- Inspect recent sensor replacements for correct installation
- Check wiring connections for errors
- Test oxygen sensors for proper function
Can I keep driving?
The car can still be driven, but it is advisable to fix the issue to avoid potential emissions problems.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer