OBD-II code · Powertrain (generic, extended)
P241B O2 Sensor Signals Swapped Bank 2 Sensor 1 and Sensor 2
The pre- and post-catalyst lambda signals on bank 2 are swapped - the upstream sensor responds like a downstream sensor and vice versa. Typically the harness was reversed during a sensor change.
Is it safe to drive with P241B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyHarness swapped during repair
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–0.8 h
- Emissions test
- Likely to fail
- Parts involved
- Oxygen Sensor B2s1, Oxygen Sensor B2s2
Related codes
- P241AO2 Sensor Signals Swapped Bank 1 Sensor 1 and Sensor 2
- P2418EVAP Switching Valve Control Circuit Performance
- P2419EVAP Switching Valve Stuck Open
- P241CThrottle Actuator Control System Ice Blockage Bank 2
- P241DSCR Inducement Forced Engine Shutdown
- P241EReductant Heater Coolant Control Valve Stuck Closed
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.