What Is an Oxygen Sensor?

Your vehicle’s oxygen sensor is part of the emissions system. It works by measuring the oxygen proportion in your engine. Internal combustion vehicles work by burning fuel. Therefore, to properly burn gasoline, most combustion engine vehicle needs a ratio of 14 grams of oxygen for every gram or gas. Your vehicle’s oxygen sensor helps keep this balance in check.

For most combustion engine vehicles, the oxygen sensor is normally located on the passenger side of the vehicle and is mounted directly onto the exhaust pipe located near the catalytic system. The moment the sensor malfunctions; your vehicle could lose up to 40 percent of its gas mileage economy since it will use up more fuel in the process.

When your car has too much air, it is said to be running too lean. On the other hand, when an engine has very little air, it is said to be running rich. A lean engine will cause jerking and hesitation during acceleration while a rich engine will cause the vehicle to run hot, causing pollution — both these scenarios will damage to your vehicle’s engine in the long run. Your vehicle’s oxygen sensor works to keep your vehicle’s emissions in check. Depending on your vehicle’s make and model, it may have one or more 02 sensors.

Symptoms of a Bad or Failing Oxygen Sensor

Running an engine with a bad oxygen sensor will not only harm your engine’s performance but also affect the environment through emissions. The following are three common symptoms of a faulty oxygen sensor.

Check engine light illuminated

The first line of defense when you have a faulty oxygen sensor is the CEL. The check engine light is triggered if you have a faulty 02 sensor. The moment you notice this light, consult a professional mechanic such as one from AAMCO Colorado perform a Check Engine Light inspection. While this light could indicate a faulty oxygen sensor, it could also mean a host of issues. In case your vehicle has a high mileage, there’s a good chance that you have a faulty oxygen sensor.

Bad Gas Mileage

If your vehicle’s 02 sensor is faulty, the fuel combustion and fuel delivery systems will be thrown off. When a faulty oxygen sensor distorts the air to fuel ratio mixture, or an excessive amount of fuel gets into your vehicle’s engine, your car’s gas mileage will significantly reduce. Excess fuel in your engine will produce a rotten egg or sulfuric smell or black smoke from your exhaust. If you are constantly re-filling your gas tank than usual, visit your local mechanic and have them check out your oxygen sensor.

Misfire and Rough Idle

As your 02 sensor gets bad, you will notice your engine run rough, have irregular idling and misfire. You’ll also notice that you have engine performance issues, such as loss of power, stalling, and hesitation during acceleration. Since your oxygen sensor output helps in controlling your engine timing, air to fuel ratio and combustion intervals, a faulty 02 sensor will disrupt these functions, causing a rough idle or irregular engine idles as well as other engine-related problems.

When Should I Replace My Oxygen Sensor?

In case your car, SUV, or truck was manufactured within the last 15 years, your oxygen sensor needs to be replaced every 60,000 to 90,000 miles. It’s important to note that the 02 sensor wears out over time and will need replacement. Replacing your 02 sensors will reduce emission levels and have your engine running smoothly. The moment you notice irregular idling, poor gas mileage and a CEL, book an appointment with your local AAMCO Colorado mechanic and have your oxygen sensor replaced.

Related: What type of drivetrain is best for winter?

Related: High Altitude Car Maintenance Tips