Auto Systems and Repair: P0141 - OBD-II Trouble Code

OBD II Fault Code

  • OBD II P0141

Fault Code Definition
The Catalyst Monitoring Oxygen Sensor evaluates the rear most Catalytic Converter's emissions-reducing capability. Code P0141 is set when the Rear Oxygen Sensor does not show signal activity indicative of closed loop fuel system operation within the required time.

Symptoms

  • Check Engine Light will illuminate
  • In many cases, no abnormal symptoms may be noticed
  • In some cases, the vehicle will fail an Emissions Test
  • In many cases, the NOx emissions will be elevated

Common Problems That Trigger the P0141 Code

  • Defective Rear Most Oxygen Sensor 
  • Faulty Rear Most Oxygen Sensor wiring or connections

Common Misdiagnoses

  • Oxygen Sensor Sensor is replaced when the problem is a defective Catalytic Converter
  • Oxygen Sensor is replaced when the problem is faulty sensor wiring or connections
  • Oxygen Sensor is replaced when the problem is an exhaust leak before the Rear Oxygen Sensor