Owning an automobile can make life much easier, but car owners have to be prepared to have repairs made to their vehicle. Properly maintaining a vehicle will help prevent major problems, but car parts will wear out eventually and need to be replaced. One very common car repair is having a faulty oxygen sensor replaced. The role of an oxygen sensor in an automobile is to monitor the oxygen level in the exhaust so the engine can determine how much fuel to combust. When an oxygen sensor stops working properly, the car will experience problems. Some of the signs that an oxygen sensor is failing and needs to be replaced include the following.

Unexplained Drop in Fuel Economy

After owning a vehicle for a while, most drivers will know how often they need to fill up their gas tanks. New vehicles also have displays that show how many miles a vehicle is able to drive per gallon of gas. If your vehicle has a sudden drop in fuel economy and you're having to fill up more despite driving the same amount, don't brush off the issue. When an oxygen sensor fails, the engine will not be able to maintain the proper fuel-to-oxygen ratio. As a result, the engine will start burning fuel at a higher rate, so the car will need gas more often.

Noticing That the Engine Is Idling Roughly

When your vehicle is turned on but is not in motion, it should idle smoothly. However, when a vehicle has a bad oxygen sensor, the engine can experience a number of issues, including rough idling. Since a bad oxygen sensor is not able to tell the engine how much oxygen is in the system, the engine can begin misfiring. If you notice that your vehicle is idling roughly, it is in your best interest to have the oxygen sensor inspected by a mechanic to see if it needs to be replaced.

Vehicle Does Not Pass Emissions

Most states require automobiles to go through emissions testing on a regular basis, and a vehicle must pass emissions before registration can be renewed. If an oxygen sensor is no longer functioning, the unregulated oxygen-to-fuel ratio can lead to problematic exhaust. Thus, your vehicle will not be able to pass emissions with a bad oxygen sensor. In the event that you receive notice that your car has not passed emissions, visit a car repair shop to have the oxygen sensor replaced.