A gasoline car's engine, just like the human body, needs oxygen to run; it is the oxygen and fuel mixture that combusts and produces the thrust needed to propel the car forward. The oxygen sensor, which is installed in the exhaust manifold, monitors the level of oxygen in the exhaust so that the air/fuel mixture can be adjusted to the correct ratio. Here are some of the telltale signs of a bad oxygen sensor:
Decreasing Fuel Mileage
Your car needs a precise mixture of fuel and air to be efficient (produce maximum power with minimum fuel consumption). This precise ratio has been pre-determined by the designers of the engine and shouldn't be interfered with. Anything that interferes with the air-fuel mixture reduces your car engine's efficiency. With reduced efficiency, your engine will not be able to consume the same volume of fuel for the same distance as it used to do. Thus, a malfunctioning oxygen sensor is one of the things you should suspect if a gallon of fuel no longer takes you as far as it used to do before.
Poor Engine Performance
The combustion of fuel in the engine is the most important factor as far as the performance of the engine is concerned. Therefore, anything that interferes with the quality of the engine will affect all aspects of the engine's performance. For example, if the oxygen sensor is malfunctioning and the air-fuel ratio is wrong, the engine may stall, misfire, or even hesitate and generally behave erratically. This makes sense because the engine will be receiving less or more fuel than usual depending on the erroneous reading it is getting from the defective oxygen sensor.
Emission Test Failure
An emission test is designed to check for pollutants exhausted by automobiles so that too many harmful byproducts of the engine don't pollute the atmosphere. In some states, your car has to pass the emission test before it is registered. If the car fails the emission test, then you have to repair and retest it again before it is registered. A malfunctioning oxygen sensor is one of the top reasons your car may fail an emission test. This happens because a wrong air-fuel mixture may result in an incomplete combustion, which lets more pollutants escape into the atmosphere than normal.
Hopefully you won't be dealing with a bad oxygen sensor any time soon. Given the importance of the oxygen sensor, however, you shouldn't hesitate in seeking auto repair services if you notice any of the signs above.
I have never been an especially handy person, but a few years ago I decided that I needed to learn more about my vehicle. I was tired of always relying on someone else to fix things, so I began reading more and more about the process. I realized that there were a lot of things that I needed to do, so I began taking a little course on at-home auto service. I still have a lot to learn, but now I can at least go through and change my air filter and check my oil. Read this blog to learn more about auto service.