OBD2 Car ScannerWhat does P0133 mean?
P0133 stands for 02 Sensor Circuit Slow Response (Bank 1 Sensor 1). The engine computer has found a problem with how fuel and air are measured or mixed. This affects fuel economy, emissions and sometimes how smoothly the engine runs.
Powertrain codes cover the engine, transmission and emissions. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Vacuum or intake air leaks
- Dirty or faulty mass airflow (MAF) sensor
- Faulty oxygen sensor or its wiring
- Fuel pressure problems (pump, filter or regulator)
- Clogged or leaking fuel injectors
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does P0133 mean?
P0133 means “02 Sensor Circuit Slow Response (Bank 1 Sensor 1)”. It belongs to the fuel and air metering group: The engine computer has found a problem with how fuel and air are measured or mixed. This affects fuel economy, emissions and sometimes how smoothly the engine runs.
Is it safe to drive with P0133?
You can usually drive carefully for a short time, but fix it soon to avoid further damage or higher fuel use.
How do I clear P0133?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- P012ETurbocharger/Supercharger Inlet Pressure Sensor Circuit Intermittent/Erratic (Downstream of throttle valve)
- P013002 Sensor Circuit Malfunction (Bank I Sensor 1)
- P013102 Sensor Circuit Low Voltage (Bank I Sensor I)
- P013202 Sensor Circuit High Voltage (Bank I Sensor 1)
- P013402 Sensor Circuit No Activity Detected (Bank I Sensor 1)
- P013502 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
- P013602 Sensor Circuit Malfunction (Bank I Sensor 2)
- P013702 Sensor Circuit Low Voltage (Bank I Sensor 2)
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.