OBD Codes List

Diagnostic reference · P0146

P0146

O2 Sensor Circuit No Activity Detected Bank 1 Sensor 3

System
Fuel and air metering (P code)
Lamp
Check Engine Light
Category
Powertrain - Fuel/Air Metering

What it means

P0146 means O2 Sensor Circuit No Activity Detected Bank 1 Sensor 3.

Where it lives

For P0146, the sensor sits on the circuit this code reports. The description of P0146 puts it on bank 1.

Check these first

  • A failed oxygen sensor on bank 1 sensor 3
  • An open signal wire on the sensor 3 circuit
  • An exhaust leak at sensor 3
  • A contaminated oxygen sensor
  • A faulty ECM input

What to do next

  1. Watch bank 1 sensor 3 for any activity on a scan tool
  2. Test the sensor 3 signal wire for an open
  3. Check for an exhaust leak at sensor 3
  4. Replace bank 1 sensor 3
  5. Verify the ECM if the sensor is good
  6. Clear the code and retest

Look up another code

Enter a full code or a symptom. Press / to search. How to read a code

Type a code above, or start from a symptom or a common code.

Updated

Generic SAE J2012 definition. Last updated 2026-10-10.