Cool 2002 Ford Explorer Sport Check Engine Light Stays On References. Check engine lightthe check engine light and malfunction lamp came on this morning in my ford. The oxygen sensor is an important component of the vehicle’s emissions control system, and it monitors the amount of oxygen in the exhaust gases.
I went to napa and replaced it with no issue. Failing that, you could try a less correct method. The light turns on when you switch on the ignition key and then it turns off:
