Reasons for oxygen sensor test


Maybe it sounds like a cliche, but car maintenance and regular engine checks can expand your car’s lifespan and add more miles. While most people completely trust their car dealer and mechanic shops, some prefer to do their own maintenance of the car. While some parts of the car are easy to understand and replace others require special knowledge and/or tools in order to complete inspections. One of these parts that requires special attention and is hard to notice for novice auto mechanics is the O2 (oxygen) sensor. This small, but very important part of the engine needs regular oxygen sensor test to determine its functionality. In order to learn how to do a sensor test or even perform an oxygen sensor replacement, one must first know how O2 sensors work.

Basically, the main reason for regular oxygen sensor test  is that O2 sensors give information about the ratio of oxygen levels in the exhaust valve compared to the levels in the air outside the engine. This is an important indicator because it applies to the fuel economy of the car. In other words, it shows how effectively the car is using its fuel. Moreover, if the car uses more fuel in the engine, oxygen levels are very low and little O2 comes out of the exhaust pipe. In this case the O2 sensor creates voltage that normally is above 0.45 volts in order to maintain proper O2 levels. On the contrary when the engine runs low, oxygen levels are very high and cause more air to come out of the engine. Consequently, the O2 sensor provides voltage lower than 0.45. Another important condition is that in order for the O2 sensor to be functional, the car engine must achieve heat of about 600 degrees otherwise it won’t show any information on the output table.

Now that we have given a glance of how O2 sensors work we can see the need for making an oxygen sensor test or in some cases even oxygen sensor replacement. This is not very complex task and you only need a quality DC voltmeter to get proper results. Furthermore, cheap voltmeter may show distorter results which may cause false need of oxygen sensor replacement. So, what indicates that the O2 sensor is working or not? The most important thing is that the voltmeter shouldn’t show steady voltage at 0.45 or lower. This means that the sensor is not working as it should. A sign that everything is alright is when the voltmeter shows osculations around 0.45 volts meaning that it is regulating the levels of oxygen. Therefore, in conclusion the main reason to perform regular oxygen sensor test is to preserve fuel economy of the car so that it can serve you longer.