Technical Definition:

Oxygen (O2) Sensor Signal Biased / Stuck Rich (Bank 1 – Sensor 1)

Technical Description:

This code is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may be slightly different depending on the model.

Possible Causes:

• Oxygen (O2) or A/F ratio sensor or sensor heater malfunction
• Open or short in O2 sensor circuit (wiring, harness)
• Fuel pressure or fuel injector problem
• Faulty PCM
• Intake air or engine vacuum leaks
• Faulty fuel injector(s)
• Fuel pressure too high or too low
• PCV system leak/fault
• A/F sensor relay faulty
• MAF sensor malfunction
• ECT sensor malfunction
• Air intake restriction
• Fuel pressure too high
• Fuel pressure sensor malfunction
• Fuel pressure regulator malfunction
• Note on some vehicles that have been modified this code may be caused by the modifications (e.g. aftermarket exhaust, headers, etc.).

Possible Symptoms:

O2 Sensor Signal Stuck Rich Bank 1 Sensor 1

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Front Heated Oxygen Sensor Bank 1
– Front Heated Oxygen Sensor Bank 1 harness is open or shorted
– Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection
– Inappropriate fuel pressure
– Faulty fuel injectors
– Intake air leaks may be faulty
– Vacuums leaks

Specific Makes:

– Excessive Fuel Consumption