2000 Explorer - check engine

Please post the exact code and any symptoms noted when the concern happens. This is NOT magic and can be a complicated endeavour. Engine size and such might help too...

Mechanical failures can and will set the CEL as well. As can cell phones, bad alternators, other electronic devices, radio waves, high voltage interference - ad infinitum. The only thing more complicated than the modern auto is the space shuttle. I doubt that your problem is as simple as changing a sensor.