What You Need To Know About the Oxygen Sensor

No vehicle owner wants to see the check engine come on. That warning sign is designed to tell you that your car needs service or repairs. Generally, when the check engine light comes on, it means that your vehicle’s emissions system is not working properly. One key reason the light goes on is due to an oxygen sensor malfunction. Learn more about this device to understand how important it is and when to get repairs.

What Is the Oxygen Sensor and What Does It Do?

The oxygen sensor is part of the emissions system in your vehicle. It measures the proportion of oxygen in your engine. The internal combustion in the vehicle works by burning gasoline. To properly burn gasoline, most cars need a ratio of 14 grams of oxygen for every gram of gas. The oxygen sensor helps keep that balance in check.

The sensor is typically located on the passenger side of the car, mounted directly onto the exhaust pipe near the catalytic converter. When the sensor goes bad, your car may lose up to 40 percent of its fuel efficiency, because your car will use too much gas.

When a car has too much air, the engine is said to be running lean. When the engine doesn’t get enough air, it’s said to be running rich. A lean engine causes jerking or a hesitation in acceleration. A rich engine mixture causes the vehicle to run hot and creates pollution. Both conditions can cause possible engine damage and poor fuel mileage. The O2 sensor keeps your emissions in check.

Your vehicle may have one, two, three or four sensors, depending on the engine type, make and model.

Signs Your Oxygen Sensor Is Faulty

You can tell your oxygen sensor is faulty by the following signs:

    1. Failure to pass the emissions test
    2. A decrease in fuel mileage
    3. Check engine light going on
    4. Poor performance, rough idling, stalling, etc.
    5. Code checker identifying O2 sensor failure

Our mechanics have the specialized equipment to test the oxygen sensor in your vehicle. Using the check engine light codes, we can quickly identify why your light is on and suggest solutions.

Guidelines for Replacing the Oxygen Sensor

How often the oxygen sensor needs to be replaced will be determined by the age of your vehicle and the type of sensor you have. Newer vehicles, those less than 20 years old, will probably need to have the sensor replaced about every 100,000 miles. Vehicles older than the mid-1990s will require replacement at 50,000 to 70,000 miles. Check the manufacturer’s recommended service for the best guidelines.

Oxygen sensors are fairly easy to diagnose and replace. Typically, you cannot repair a faulty O2 sensor. It must be replaced because of the technology and materials in its housing. There are some DIY places that will tell you how to clean the sensor to get a few more miles out of it, but you’re only delaying the inevitable. There’s no guarantee that cleaning the sensor will fix the problem. You may also damage the sensitive technology.

Once you know that you have a bad sensor, it’s much like changing a spark plug. Some people do choose to replace the sensor themselves, but you do need a special socket to do so. It’s important not to get any oil or grease on the sensor. A mechanic can handle the job and make sure it’s installed correctly.

Don’t Ignore the Check Engine Light

The check engine light is telling you your car has a fever. It’s sick. It might be something minor, such as a loose gas cap. It could also mean a faulty catalytic convertor or wires that have been damaged. In some cars, a change in humidity can cause the check engine light to come on. Without a proper diagnosis, you can’t be sure what’s wrong. Knowing why the check engine light is on can give you peace of mind, especially after making the necessary repairs.

Sun Devil Auto has 19 locations in the Phoenix Area that provide diagnosis, service and repairs for all makes and models. Find the store closest to you, make an appointment and let us help you keep your car in peak performance.