You can find an oxygen (O2) sensor in your vehicle's exhaust system. It looks similar to a spark plug and is the same size. It ensures that the oxygen in your car’s engine or the air-fuel ratio is optimal. The oxygen sensor exists in two different settings concerning the converter. You can arrange it before the converter or after the converter. Setting it before the converter is called upstream, and setting it after the converter is called downstream. The oxygen sensor gets its data and communicates within the system with the help of an electrical signal or a voltage signal. It sends the data to the central computer located in the engine, and the computer ensures that the mixture of oxygen and fuel is in optimal amounts to keep the engine running in top condition.
The oxygen sensors in your car are not such an item that they need to be replaced regularly without any issue. Unlike the air filters or the oil in your car, you only have to replace the oxygen sensors when they malfunction. If the oxygen sensor fails and does not work properly, the vehicle won't be able to correctly tell the ratio of air and fuel, which can also lead to excessive emissions from the vehicle. This failure to work seamlessly can also damage other components of your car, such as the catalytic converter.
When an O2 sensor in a vehicle becomes faulty or deteriorates, it can exhibit several symptoms including: