P0041 — O2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 2 Sensor 2

O2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 2 Sensor 2. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

• Check-engine warning for apparently exchanged oxygen sensor signals between bank 1 sensor 2 and bank 2 sensor 2.
• Usually little immediate change in drivability, but catalyst monitoring and emissions testing may be affected.

Possible causes

• Cross-connected bank 1/bank 2 sensor 2 plugs after repair, when connectors permit interchange.
• Crossed or improperly repaired wiring or a sensor signal routing fault.
• An engine ECU fault is uncommon; diagnose physical connections first.

What to check

• Confirm P0041; verify the engine actually has both banks and identify bank 1 cylinder position from OEM documentation.
• Trace bank 1 and bank 2 sensor 2 plugs, especially after recent exhaust work; inspect for swapped identical connectors.
• Compare physical wiring positions and connector pinouts against the vehicle-specific diagram.
• Observe signals with a capable scan tool using a manufacturer-supported identification test; avoid creating uncontrolled exhaust leaks.
• Repair misplaced or crossed wiring and confirm the corrected signals; avoid replacing sensors solely because this DTC is stored.

Also written as: P0041-00, P004100, PO041 (some scan tools add the fault-type byte, e.g. -00).