Oxygen sensors are a vital component of your emissions system. Mustang oxygen sensors can fail or become damaged over time causing your Malfunction Indicator Light (MIL) to turn on. Your Mustang's O2 sensors read the amount of oxygen in your exhaust to adjust air/fuel ratios. A malfunctioning sensor can cause lean and rich conditions while illuminating your check engine light. Fix yours today with a replacement sensor or extension harness to fit your application!