Auto Systems and Repair: P0154 - OBD-II Trouble Code

OBD II Fault Code

  • OBD II P0154

Fault Code Definition
Code P0154 is triggered when the Oxygen Sensor signal that is sent to the Powertrain Control Module remains at or near the .450 set voltage point. 


  • Check Engine Light will illuminate
  • In many cases, no abnormal symptoms may be noticed
  • In some cases, the engine may hesitate during acceleration
  • Poor fuel economy

Common Problems That Trigger the P0154 Code

  • Defective Oxygen Sensor
  • Faulty Oxygen Sensor wiring or connections
  • Missing Oxygen Sensor Heater Circuit Power Voltage

Common Misdiagnoses

  • Oxygen Sensor is replaced when the real problem is a vacuum leak
  • Oxygen Sensor is replaced when real problem is a poor connection