P0133 O2 Sensor Circuit Slow Response Bank 1 Sensor 1

Definition: The P0133 code indicates that the oxygen sensor located in bank 1, sensor 1 is taking longer than expected to respond to changes in the air-fuel mixture. This slow response can affect engine performance and emissions.

p0133: O2 Sensor Circuit Slow Response Bank 1 Sensor 1

Typical Severity: Moderate

Common Causes

P0133 – O2 Sensor Circuit Slow Response (Bank 1, Sensor 1)

• Common causes of P0133:
  • Faulty oxygen sensor
  • Wiring or connector issues in the oxygen sensor circuit
  • Vacuum leaks in the intake manifold
  • Exhaust leaks near the oxygen sensor
  • Fuel pressure too high or too low

 

Common Misdiagnosis

OBD2 Code: P0133

Description: O2 Sensor Circuit Slow Response Bank 1 Sensor 1

Common Misdiagnosis: Replacing the oxygen sensor without checking for exhaust leaks, vacuum leaks, or issues with the mass airflow sensor that could affect the sensor’s performance.

 

Common Diagnostic Steps

OBD2 Code: P0133

Description: O2 Sensor Circuit Slow Response Bank 1 Sensor 1

• Check for any exhaust leaks before the sensor.
• Inspect the wiring and connectors for damage or corrosion.
• Test the oxygen sensor’s response time using a scan tool.
• Verify proper fuel pressure and injector operation.
• Ensure there are no vacuum leaks in the intake system.
• Examine the Mass Air Flow (MAF) sensor for contamination or faults.
• If necessary, replace the oxygen sensor with a new one.