P0133

What it means

This code means the oxygen sensor before the catalytic converter on the first bank of cylinders is responding too slowly to changes in the exhaust gas. This sensor helps the engine adjust its fuel mixture, so a slow response can lead to inefficient operation.

Is it safe to drive?

While often drivable, a slow O2 sensor can lead to poor fuel economy and increased emissions. Prolonged driving could potentially damage the catalytic converter.

Most likely causes

• Aging/Contaminated O2 Sensor (Bank 1 Sensor 1)

  high

  Over time, the sensor can become sluggish due to carbon buildup or internal degradation, causing it to react slowly.

• Exhaust Leaks

  medium

  Leaks near the sensor can dilute the exhaust gas, making the sensor respond inaccurately or slowly.

• Rich or Lean Running Condition

  medium

  Underlying engine issues causing a consistently rich or lean condition can make the O2 sensor appear slow.

• Wiring/Connector Issues

  low

  Damaged or corroded wiring can impede the sensor's signal, leading to a perceived slow response.

Related help

• Full P0133 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?