The automotive oxygen sensor, as the core feedback sensor in the automatic control system of electronic fuel injection engines, is crucial for regulating exhaust emissions. However, it is worth noting that oxygen sensors are also vulnerable components with a certain service life. So, how is the replacement cycle of car oxygen sensors determined, and does it help save fuel after replacement?

Generally speaking, when the mileage of a car exceeds 100000 kilometers, it is recommended to check and consider replacing the oxygen sensor. Of course, the specific timing of replacement still needs to be determined based on the actual situation. By observing the color on the top of the oxygen sensor, its working status can be preliminarily judged, and under normal circumstances it should be light gray. If the top appears white, it may indicate that the oxygen sensor has been contaminated with silicon to a certain extent and needs to be replaced in a timely manner; If it appears dark brown, it may be caused by lead pollution and also needs to be replaced; The black top is usually caused by carbon deposits, and cleaning is sufficient.

Whether replacing the oxygen sensor can save fuel depends on the specific situation. When the oxygen sensor ages to a certain extent, it will have a significant impact on the air-fuel ratio of the car, leading to an increase in fuel consumption. At this point, replacing the oxygen sensor with a new one can effectively improve the air-fuel ratio, thereby achieving fuel efficiency. However, please note that if the rear oxygen sensor is replaced, its main function is to monitor the operating status of the three-way catalyst, so replacing it will not directly produce fuel saving effects.