The Oxygen Sensor and How it Works

An oxygen sensor is also known as an (O2 Sensor) which is a vital component of any vehicle’s emission system.

Some old vehicles have fuel injection systems, while all new vehicles have them, in which a computer will regulate the amount of fuel that is delivered to the engine. The computer will communicate with the sensors throughout the system to determine how much fuel to deliver to the engine and of course, how frequently.

The oxygen sensor is found in the exhaust manifold.

One end of the oxygen sensor will detect the oxygen levels in the exhaust flow. The other end will connect to the wiring that gives all the information to the computer.

The computer will then use the sensor readings to make sure that the engine is getting the right amount of fuel. If there is too much or too little fuel, the readings from the oxygen sensor will change, and this will then make the computer readjust the amount of fuel that is being delivered to the engine.

An oxygen sensor will fail from time to time. Whenever the sensor malfunctions, all the important feedback about the engine performance will then be lost. This will then cause the computer that runs the electronic fuel injection system to have absolutely no idea of how much fuel to deliver to the engine.

An O2 sensor always has a mileage rating. This indicates to us how long the sensor is expected to last. There are a few different ways of finding this information.

A vehicle owner’s manual or a shop manual should state what the lifespan of the oxygen sensor is expected to be. If none of these books are available then the dealership will be able to look up the information for a specific vehicle. Also auto parts stores will have the information. In general the oxygen sensor should last approximately 30,000 miles in older vehicles and 60,000 miles in newer vehicles if not more, but be sure to check your cars manual or techincal service bulletin for the right time to change it.

When you find out the mileage rating for the O2 sensor in your vehicle, it is always a good idea to keep all records of when any mechanical work is done on the vehicle. Therefore if you know at least when the sensor was replaced in the first place you will know when it needs to be replaced again.

If you replace the oxygen sensor regularly it will help:
- Maintain your gas mileage.
- Help prevent other related car troubles.
- Helps prevent failed emission tests due to malfunctioning oxygen sensors
- Help prevent poorly running engines with rich gasoline mixes.