How Can You Tell If A Car Sensor Is Bad?

The oxygen sensor is responsible for monitoring the air-fuel ratio in a vehicle. The work of an oxygen sensor is important to the proper functioning of a car. This is because, without the oxygen sensor, the engine of the vehicle cannot determine the ratio of gasoline and air present. This leads to problems with the rich mixture and lean mixture. A rich mixture occurs when the ratio of fuel compared to the air is too much. This typically slows down the vehicle. A lean mixture occurs when there is not enough fuel, and it leads to pollution of the car engine. This is why it is important to know when the oxygen sensor of your car is bad. We have highlighted five signs that the oxygen sensor of your car is bad below.

Signs That Your Car Sensor Is Bad

If your car is showing any of the signs below, you need to check out its oxygen sensor.

  • Glowing Check Engine Light: The check engine light will reflect on your dashboard if you have a problem with parts of the vehicle. One of the reasons why this light reflects is because of a faulty oxygen sensor. It could also be because of other problems, so it is important to get a car mechanic to check out the car.
  • Increase in Gas Consumption: If you notice that you are spending more on gas than you usually would, it is an indicator of a bad oxygen sensor. Whenever the air-fuel ratio is not correct, the engine loses its efficiency leading to the consumption of more fuel. If this is not checked, you might end up needing double of what is required for your usual mileage.
  • Funny Sounds: A faulty oxygen sensor can cause the engine of a vehicle to develop issues. This typically results in strange and funny sounds, which are unpleasant. This occurs as the oxygen sensor affects actions such as engine timing and combustion interval. Apart from the sounds, you might notice a reduction in acceleration as well as stalling.
  • Emission Test Failure: If your car fails an emission test, it is most likely a result of a faulty oxygen sensor. You are prone to deal with issues like the foul smell as well as the emission of a high volume of carbon monoxide. This will negatively impact your driving experience.
  • Old Vehicle: If your vehicle is old, the oxygen sensor is definitely not as effective as it used to be. Substances like lead, sulphur, oil ash and fuel additives will cake the sensor, reducing its functionality. An old oxygen sensor should be replaced with a newer one in order to keep your car running in great shape.


If your car is suffering from any of the signs listed above, it is important to contact a car mechanic to carry out repairs as soon as possible. This will help you to avoid further problems that might arise if you leave the oxygen sensor unchecked.