5 Symptoms of a Bad Oxygen Sensor
Your vehicle’s oxygen sensor monitors the efficiency of your combustion, but like any other type of sensor, it can eventually fail. Ignoring a bad oxygen sensor can lead to growing problems that can affect performance and fuel economy.
Learn how to recognize the subtle symptoms that come with a bad oxygen sensor. Realizing it too late could mean having to deal with a much more expensive repair later.
How an Oxygen Sensor Works
Your car’s internal combustion engine constantly produces exhaust gases after the air-fuel mixture in the cylinders ignites. These gases contain a variety of elements, including carbon and oxygen. The exhaust manifold has a component called an oxygen sensor that monitors the oxygen level in the exhaust gases leaving the engine. This is the oxygen that wasn’t burned during the original air-fuel combustion.
Once the oxygen sensor detects the oxygen level, it sends this information back to the engine control unit, which is of course the central computer that manages all the systems in the vehicle and communicates with the various sensors located within the system.
Once the engine control unit receives information about the oxygen content in the exhaust gases, it knows if the engine is burning too much or too little fuel. For example, lean burn occurs when there is more air than fuel in the cylinder chamber.
The exhaust gases produced by such combustion contain more oxygen. When the oxygen sensor detects this and sends the data to the engine control module, the computer adjusts the injector timing and engine operation appropriately. In this way, the mixture in the engine is optimal for combustion.
Most Common Symptoms of a Bad O2 Sensor
The oxygen sensor is a critical part of your engine. If the oxygen sensor does not work properly for any reason, it can affect the entire combustion process. This can then cause all kinds of problems in your engine while driving.
Fortunately, these symptoms are easy to recognize, so you know there is a problem somewhere in your engine or its components. Below are the 5 most common symptoms of a broken or worn O2 sensor.
1) Check Engine Light
As we have already mentioned, the oxygen sensor has a big impact on the air-fuel combustion process. If the sensor detects that there is less oxygen in the exhaust gases after combustion, the engine control unit will try to correct this.
However, if the oxygen sensor is not working properly, the engine control module does not know how to solve this problem. The module then detects that there is a problem with the motor. This will cause the Check Engine Light to illuminate on the dashboard.
Codes P0030, P0031, P0130, P0131, P0132, P0133, P0134, P0137, P0140, P0141, P0161, P0172, P2195, and P2270 are examples of diagnostic trouble codes that may indicate an oxygen sensor problem.
2) Poor Fuel Economy
If you have a rich mixture in one of the combustion cylinders, that means there is more fuel than air. If the oxygen sensor is defective, this will not be detected by the sensor. And you will end up with a situation where more fuel is burned in the engine than necessary. The result is poor fuel economy and higher gas bills.
3) Rough Idling
A rough idle means that the engine doesn’t turn over smoothly when the car is parked or stopped. The normal speed for an idling engine is below 1,000. However, a rough idle occurs when the engine RPMs rise to 2,000 or 3,000.
This can be a symptom of many different kinds of car problems, such as a bad oxygen sensor. Engine control is more difficult for the engine control unit to handle. Then there are combustion intervals that lead to misfires.
4) Weak engine performance
When the normal combustion process of the engine is disturbed, the engine performance will be reduced. This happens when the oxygen sensor fails. You will notice this while driving. Limited or no acceleration when you step on the accelerator.
5) Failing an Emissions Test
The oxygen sensor is located in the exhaust system manifold and therefore helps with emissions control. If you live in a state that requires regular emissions testing, it may turn out that your oxygen sensor is faulty if you fail an emissions test.
It doesn’t necessarily have to be oxygen sensor related, but a mechanic can tell you why your vehicle failed a test.
