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4 Symptoms of a Failing Oxygen Sensor

By maigne on September 14th, 2020


What are the signs that your oxygen sensor is failing?

  1. Poor Fuel Economy
  2. Rough Idling
  3. Weaker Engine Performance
  4. Increased Harmful Emissions

One of the worst fears that every car owner has is the time when the “Check Engine” light goes on. It’s an alert that warns the driver of a problem within the engine. Often it means that the car is experiencing some symptoms of a failing oxygen sensor.

There are times when it’s just a small malfunction with the Oxygen sensor itself, however, in most cases, it indicates that your vehicle is not running as optimally as it can. This results in excessive unnecessary emissions.

Aside from the engine light, be mindful when you experience these things for it may mean that your oxygen sensor is already failing!

Poor Fuel Economy

Oxygen is present in gasoline-powered engines when they burn off the gasoline. It’s the result of many variables. These variables include engine temperature, barometric pressure, air temperature, altitude, and a few others.

14.7:1 is the ideal oxygen to gasoline ratio. It’s almost always around that mark. It varies depending on the type of gas used and the make of the engine. Having more oxygen in the engine is called a rich mixture while having a lean mixture means having less oxygen present. Both are bad for your vehicle and it can also damage the environment. Both conditions generate more pollutants that can cause problems both in your engine and in the environment. The lean mixture, in particular, can produce nitrogen-oxide pollutants, something that can decrease the vehicle’s overall performance and even damage the engine.

Oxygen sensors help determine whether or not your car has rich or lean mixtures. It also has a system that indicates how much fuel your engine needs to expend. When this system malfunctions, the engine is forced to guess how much gasoline to use up.

Rough Idling

Normally, idling your engine will put its RPM rate at just about under 1,000. When there’s a problem with your oxygen sensor, however, it can shoot up to 2,000 or even 3,000 RPM.

When your car is experiencing rough idling, it will not feel smooth. The RPM will be volatile as it goes up and down. Because of this, it’s also very easy to notice making it a good warning sign that something is wrong with either your oxygen sensor or your engine as a whole.

This can be a sign that the Oxygen sensor is having some problems because as mentioned above, it helps indicate how much gas the engine needs to burn up. When it fails the car’s internal engine can’t calibrate the right oxygen to fuel ratio.

Weaker Engine Performance

When the internal combustion processes of an engine have an anomaly, its performance will be heavily influenced as well. This will happen a lot of times with bad oxygen sensors.

The most major problem caused by bad oxygen sensors is that the engine will not be able to calculate effectively how much gas is optimal to burn. It prevents any rich or lean mixtures from happening, thus it keeps the engine’s combustion process clean and optimal.

When this sensor fails, it brings with it a lot of potential problems within the engine. In a way, the sensor ensures that the engine knows what it’s doing. Without it, the whole combustion process relies on inaccurate data and will just fall back to a default setting—something that can be detrimental when it’s dealing with a sensitive engine.

Increased Harmful Emissions

Because the sensor no longer controls the gas that is put into the engine, it will result in either a rich or a lean mixture. This then leads to the production of different pollutants. Not only will this be harmful to the environment. But it will also fail to pass smog according to the Environmental Protection Agency.

Bear in mind that around 50 to 60% of all smog test-related failures are linked to defective oxygen sensors. In the Philippines, emission tests are mandatory, particularly in the renewal of a car’s registration. If you fail this test, your vehicle might no longer be allowed to roam the streets.

Key Takeaway

It is very important to make sure that your oxygen sensor is not malfunctioning and is in prime condition. A lot of what an engine’s combustion process works with relies on the sensor bringing accurate data to keep the whole system clean.

When it goes bad, engine performance and safety measures will surely follow. That is why you have to be vigilant and regularly look for symptoms of a failing oxygen sensor. Spotting them early will help you avoid numerous and more expensive problems.

As a side note, vehicles need to have their oxygen sensors replaced every 100,000 km that they have been in use for it still wears over time. This might even be another reason why it’s starting to fail!

At the first sign of the symptoms that we mentioned above, you should immediately bring your car for a maintenance checkup so that it won’t experience any more problems in the future!

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