Common Symptoms of Faulty Oxygen Sensor
The oxygen sensor may look like a minor car component, but it plays a very crucial role in your vehicle. When the oxygen sensor fails, it causes several issues such as engine misfire, low fuel economy etc. Hence, drivers should familiarise themselves with the symptoms of the faulty oxygen sensor, which will help them to identify the issue before it’s too late.
This guide provides you with everything you need to know when the oxygen sensor should be replaced.
What is an Oxygen Sensor
The oxygen sensor plays an important role in your vehicle’s combustion system. The action requires a combination of air and fuel to generate the explosion in addition to the spark. If the air-fuel ratio is not balanced, the engine is not working properly and it will not produce the required power. You can also clean the car’s oxygen sensor to extend its life.
Purpose of Oxygen Sensor
The oxygen sensor is responsible for regulating the amount of air/fuel ratio that enters the engine. However, if the oxygen sensor is not functioning properly, it gets disrupted and causes engine performance issues.
This is why it is essential to keep an eye on the oxygen sensor and be aware of all the symptoms of the faulty oxygen sensor that could indicate that your engine’s oxygen sensor is on the verge of deteriorating
How Long Do O2 Sensors Last

There are different types of oxygen sensors available in the market. Typically, oxygen sensors should last between 48,000 and 80,000 km or nearly three to five years. However, that range differs significantly depending on the brand of your vehicle and where you drive.
Therefore, you should not rely on this range threshold. Instead, you should consult your mechanic or consult your vehicle’s owner’s manual to get an idea of what the manufacturer recommends.
When to Replace Oxygen Sensor
Since the oxygen sensor is not designed to last forever, there will be a time when you will need to replace it. Although there may be a threshold for when the sensor might deteriorate, there are sudden instances where the oxygen sensor fault symptoms before it should.
Oxygen Sensor Fault Symptoms
Let’s take a closer look at some of the common oxygen sensor fault symptoms that your oxygen sensor needs to be replaced:
Reduced Fuel Consumption
Since the oxygen sensor is responsible for monitoring the air and fuel mixture, it has a lot to do with the vehicle’s gas mileage. Hence, with a bad O2 sensor symptoms, your engine uses more fuel than it should and makes your car less fuel efficient.
Engine Check Light

One of the first and most common things you will sometimes notice when the oxygen sensor goes bad is a check engine light. The oxygen sensor check engine light helps to draw your attention to internal car issues.
Sometimes the check engine light could be related to a minor issue, but it could be related to a major issue. Therefore, auto experts always recommend not ignoring a check engine light.
Since the check engine light is triggered due to various issues, you need to confirm whether your problem is related to an oxygen sensor or not. One way to do this is to use an OBD scanner to scan your vehicle’s internal computer and translate fault codes into messages that might help you identify the culprit.
Strange Engine Noises
You may also notice the poor engine performance due to a bad oxygen sensor. A rough engine is not normal, indicating that there is an internal problem. In most scenarios, the problem can be related to several issues occurring at the same time. However, it should be noted that the oxygen sensor could be one of those culprits.
Hence, whenever you notice strange squealing noises coming from the vehicle, you should take the problem seriously as it usually indicates an internal problem. However, a regular maintenance checklist can help you catch the problem sooner rather than later.
Reduced Engine Power

If the failing oxygen sensor has impacted fuel economy, you will also notice reduced engine power. This is because the engine will continuously demand more fuel, which is why it won’t have the right mixture to produce the optimum power by using the minimum amount of fuel.
Engine Misfire
A faulty oxygen sensor can cause a car engine to fire on rare occasions. Engine misfires occur when the engine does not receive the necessary components to perform the correct explosion.
For example, the engine needs a specific amount of air, fuel, and the right spark at the right time. If any of the mentioned components did not occur, you would face engine misfires.
Oxygen Sensor Replacement Cost
Replacing the oxygen sensor isn’t cheap all the time. Typically, the starting price of the engine oxygen sensor is AED 180. The price range also differs significantly depending on many factors such as car makes, model etc.
Common Oxygen Sensor Fault Codes

Here are some standard car diagnostic codes that appear due to oxygen sensor fault symptoms:
- P0135: Oxygen sensor before catalytic converter 1 heater circuit/open
- P0175: System too rich
- P0713: Fuel supply correction malfunction
- P0171: System too lean
- P0162: O2 sensor circuit malfunction
How to Change a Faulty Oxygen Sensor

There is no temporary fix for a bad O2 sensor; hence, you need to replace it with a new one. Here are the steps to correctly change the oxygen sensor of a car:
- Find out the oxygen sensor location in your car and look for a part that has a great resemblance to a spark plug.
- Cut the electrical connection of the O2 sensor with the help of a flat screwdriver.
- Unscrew the oxygen sensor from the exhaust pipe with the help of a wrench or a special socket to remove it.
- Compare your new oxygen sensor to the old one.
- Cut off the old connector from the faulty oxygen sensor, strip the wires and connect them to the new oxygen sensor.
- Reverse the steps used to remove the oxygen sensor and install the new part. Add a small amount of anti-seize to the threads of the new sensor. Screw it clockwise and tighten it with the socket or wrench.
- Reconnect the electrical connections again.
- Turn the ignition key, but don’t start the car. Use the diagnostic scanner/reader to clear the code from the car’s computer.
- Start the car. You should notice an immediate improvement.
The oxygen sensor is an extremely important component of your vehicle. It is responsible for monitoring the air and fuel mixture to help your engine run smoothly and prevent sudden breakdowns. As we mentioned earlier, the oxygen sensor plays an important role, and if it goes bad, your overall engine performance is affected.
Besides, if your car is facing other major issues then consider replacing it with a used car in the UAE at affordable rates.
If you find this guide useful, stay tuned to the UAE’s popular car blog for more information.