The oxygen sensor in a car has a very critical role to play and therefore it is important that we make sure that your vehicle has a perfectly running oxygen sensor all the time. So, it is important to understand the common symptoms that help you understand when and why you need to replace the oxygen sensor. 

1. Failing the emission test

When the oxygen sensor fails, your car won’t pass the emission test. As the communication will be disrupted with the engine to tell how many bad and harmful gases are leaving through the existing system. Thus, it is recommended to consider checking the oxygen sensor in such a case. 

2. Check engine light illuminating

When the check engine light illuminates, it indicates a number of potential culprits. However, at times it can be difficult to determine what the culprit is unless you have a scanner that can go inside the vehicle’s computer and determine the faulty components.

3. Engine misfiring and stalling

Yet another important symptom that might notice in oxygen sensor failure is engine misfiring and engine stalling. If you notice that the engine is not operating properly and your vehicle frequently stalls, ensure to check the sensor and replace it.

4. Reduced fuel economy

Reduced fuel economy is another symptom that is related to some faulty components, which means you cannot immediately replace the oxygen sensor because you notice that your vehicle uses too much fuel. Instead, you should consider consulting your mechanic and ask him to take a quick look and perform the third inspection to confirm the faulty component before deciding on any repairs. 

5. Loud engines noises

There can be times when you hear weird noises coming from the engine compartment and there can be many reasons for the same, one of which could be a faulty oxygen sensor.

6. Weird exhaust smoke

The exhaust should not have any colour. Bt if you notice black colour smoke then it is a serious problem and you should consider getting it checked.

7. Rotten egg smell from the exhaust

When the oxygen sensor fails, it allows the wrong chemicals to leave the vehicle through the exhaust smoke and the easiest way to detect problems with the exhausted system, including the faulty oxygen sensor, is when you notice a strong rotten egg smell that indicates some sulfur in the exhaust smoke. 

8. Damages in the catalytic converter

Sometimes, problems in a simple component like the oxygen sensor can lead to causing problems with the most expensive components like the catalytic converter. 


Therefore, it is always advisable to consider checking the oxygen sensor when you run out of potential causes on noticing any problems like overheating, problems with the cooling system etc. with your car.