Oxygen sensors are relatively inexpensive and changing them regularly can help prevent more costly problems. They check the ratio of air and gasoline in your vehicle’s engine so its computer can adjust it, if needed. The amount of oxygen in an engine depends on the surrounding air temperature, the altitude, the barometric pressure, the engine temperature, the load on the engine, and more. Too much fuel left over after combustion is called a rich mixture. A lean mixture without enough fuel produces more pollutants with nitrogen oxide. Here are some of the most common signs that your oxygen sensor is bad.

• 1. A Glowing Check Engine Light
• 2. Bad Gas Mileage
• 3. An Engine That Sounds Rough
• 4. An Emissions Test Failure
• 5. An Older Vehicle