Bad O2 Sensor Symptoms Causes Replacement Cost

Is Your O2 Sensor Failing? Here Are the Symptoms, Causes, and Replacement Cost

Have you noticed a steep mileage drop lately? Has your Check Engine Light come on? You might be dealing with a bad oxygen sensor. If you think the O2 sensors are failing, swap them out quickly to avoid costly repairs later.

In this blog, learn about bad O2 sensor symptoms, possible causes, O2 sensor replacement costs, and what to do if you have experienced repeated sensor failures.

What Does the Oxygen Sensor Do?

The O2 sensor measures the oxygen content of the exhaust system's gases. The ECU uses this information to determine the correct air/fuel mixture needed in the combustion chamber for the engine to run optimally.

Oxygen sensors come in various types, including heated and unheated sensors. Heated O2 sensors are commonly used in today’s vehicles. They have an internal heating element for more accurate temperature readings. On the other hand, unheated O2 sensors lack a built-in heating mechanism, so they rely on the hot exhaust gases to activate them.

Regarding positioning, upstream O2 sensors are closest to the engine, while downstream sensors are closest to the tailpipe. Most modern vehicles have two or more O2 sensors.

What Are the Symptoms of a Bad Oxygen Sensor?

Properly functioning O2 sensors help make sure your engine operates effectively and efficiently. If the air-fuel ratio in the combustion chamber is incorrect because of a bad O2 sensor, there will be incomplete combustion. This can lead to various issues.

Here are some common bad O2 sensor signs to watch out for.

• Check Engine Light on—A Check Engine Light is one of the most common signals of a faulty O2 sensor. Your car’s ECU constantly monitors the conditions of the O2 sensors and will throw a Check Engine Light on the instrument cluster if it detects an issue.
• Poor engine performance—If the engine is not fed the correct mix of fuel and air due to faulty oxygen sensors, you will notice serious performance issues. In terms of performance, a bad O2 sensor reduces power, produces poor acceleration, and even rough idling.
• Reduced fuel economy – A faulty oxygen sensor can cause your car to consume more fuel than usual. This happens as a result of the fuel-air mixture being too rich. Over time, you find yourself spending more and more at the pump.

What Causes an O2 Sensor to Go Bad?

Oxygen sensors can fail for various reasons. Understanding why they fail can help you avoid the problems before they start. These are some of the common causes of O2 sensor failure:

• Age and mileage—Oxygen sensors operate in extremely harsh conditions. They are constantly exposed to extreme temperatures and must provide highly accurate readings. As a result, they are prone to failure over time.
• Electrical issues—Electrical gremlins can wreak havoc on any sensor, and the O2 sensor is no exception. For example, broken connectors, faulty wiring, or bad insulation can cause electrical faults that damage oxygen sensors.
• Internal contaminants—Particles generated in the engine can damage the O2 sensors and render them ineffective. For example, leaking head gaskets can let coolant into the exhaust chamber. This residue gets to the sensors and causes them to give bad or no readings.

How Long Can You Keep Driving with a Bad O2 Sensor?

A bad O2 sensor may not stop your car from moving, but driving with faulty oxygen sensors will do more harm than good. PartsHawk recommends changing O2 sensors as soon as you determine an issue. The sensors generally have a lifespan of anywhere between 60,000 to 150,000 miles. It’s a huge range, 

Failing oxygen sensors can lead to incomplete fuel combustion, damaging the catalytic converter. They are also not cheap to replace. Moreover, broken O2 sensors will result in higher levels of exhaust emissions, which can cause your car to fail an emissions inspection. 

Bad O2 Sensor Replacement Cost

You should replace bad oxygen sensors right away. In most cases, you’ll only need to replace the broken sensor, not the whole set.

How much it costs to replace bad oxygen sensors depends on the vehicle type and whether you do the job yourself or hire a professional. Sensor prices vary by vehicle. Most cost between $40 and $200. If you let a mechanic do the job for you, the cost can range from $150 to $600, including parts and labor. However, the process is fairly simple, and anyone with a little mechanical knowledge can do it in a couple of hours.

Do I Need to Do Anything After Replacing an O2 Sensor?

After installing the new sensor, you must clear the oxygen sensor error code. You can use a scan tool to do this or, in some cases, simply disconnect the battery for a few minutes. A quick Google search should give you all the info needed for your specific make and model.

How to Deal with Repeated O2 Sensor Failures

If you have experienced repeated oxygen sensor failures, it may be something as simple as poor manufacturing. The best idea is to get O2 sensors from a reliable, quality parts supplier like PartsHawk.

Another reason for repeated bad O2 sensor symptoms could be the existence of other engine faults that are affecting the sensors. In any case, many symptoms are the same as those from other engine issues. Always scan the vehicle for error codes before randomly replacing parts. 

Replacement O2 Sensors from PartsHawk

Driving with bad sensors can shorten your engine’s lifespan, hurt its performance, reduce fuel efficiency, and cause your vehicle to fail an emissions test. That’s why it’s essential to check and replace your sensors regularly. More importantly, you should act quickly when you notice bad sensor signs.

At PartsHawk, we offer high-quality O2 sensors from top brands. All our parts meet manufacturer specifications. Order your replacement oxygen sensor today and take advantage of great prices and fast delivery.