“Pay attention to your check engine light and your vehicle’s sensors or you could pay the price,” says Bryan Gregory, Advance Auto Parts’ director of consumer education.

“Sensors monitor air-fuel mixture, engine temperature, air-flow, wheel speed and more, so essentially they are telling your vehicle’s computer what to do,” Gregory states. “If your sensors fail, your engine may experience poor mileage and performance, and in severe cases your engine may fail altogether.”

In most cases, a “check engine” light will illuminate to let you know that there is a problem. Any Advance Auto Parts store will scan your OBD (On-Board Diagnostic) port at no charge and print out the fault code to help you determine your next steps.

Access to these sensors is usually the most difficult part of the replacement process. In the case of oxygen sensors, the project can be simplified by using a specially designed O2 sensor socket that accommodates the sensor wiring. A Repair Manual specific to your vehicle can be very helpful when replacing sensors.