What does code P0140 mean?
No activity detected from the rear oxygen sensor; signal remains flat
OBD-II Code
P0140 — Oxygen Sensor Circuit No Activity Detected Bank 1 Sensor 2
No activity detected from the rear oxygen sensor; signal remains flat
Common symptoms
- Few symptoms
- mixture not properly adjusted
- check engine light
Possible causes
- Failed sensor
- cut wiring
- exhaust leak
Initial recommendation
Check wiring continuity, inspect exhaust leaks, replace oxygen sensor.
Safety notice
This information is for guidance only and does not replace a physical vehicle inspection or diagnosis by a qualified mechanic. If the vehicle has severe power loss, smoke, a fuel odor, overheating, brake or steering problems, or any unsafe behavior, avoid driving it and seek professional inspection.
Analyze this code with MecaOBD
Use the app to combine code P0140 with your vehicle's actual symptoms for more complete diagnostic guidance.
Go to the app View more codes