The oxygen sensor is not a regular maintenance part and doesn’t need replacement unless it’s malfunctioning or damaged.
The oxygen sensor is a vital part of the fuel and emissions systems because it monitors the oxygen amount in the exhaust and sends the information to the engine computer to adjust the air fuel mixture. If the sensor fails, the computer won’t be able to set the air-fuel mixture correctly which could cause reduced fuel efficiency, higher emissions and damage to other parts of the system.
Modern cars have a particular warning light that signals when an engine light fails. If your car doesn’t have that particular warning light, then it might be connected with the check engine light to trigger any failure.
An illuminating check engine light can indicate various simple or severe issue – such as a malfunctioned catalytic converter, or something simple as a loose gas cap. You need to take the car to a service shop if the light appears and a professional will decode the signal using a device. Many repair shops do this service for free.
Other signs of a bad oxygen sensor are rough idle, engine misfire, reduced power, increased fuel consumption. These symptoms could also indicate other problems, so it’s better to have the car checked by a professional to determine what the exact issue is. According to EPA, replacing a faulty oxygen sensor can increase fuel efficiency up to 40 percent. So on the contrary, a bad sensor can make your engine burn much gas than usual.
A new oxygen sensor costs around $100 to $300 depending on car model and sensor type. Excluding the parts price, you’ll need to spend additional money to the mechanic who will do the replacement job.