When the check engine light comes on for the 2016 ford explorer it is because the onboard computer has detected a problem and it can mean any number of things. for example it can mean that there is a problem with the 02 sensor, battery, spark plugs, transmission, ignition system, emissions control, loose or missing gas cap, etc. some of these are easy and simple to fixand others are expensive and complicated. if there is a problem with the spark plugs, the cost of a new spark plug is anywhere from $ 5 to $ 10 and only takes about 5 minutes or so to fix. if the problem is with the gas cap, justsee if you can tighten it or if a new one needs put on. the cost of a new gas cap is between $ 10 to $ 25 or so.
If the check engine indicator on the gauge cluster is lit up, this indicates that the onboard computer has detected a problem. the trouble code can be read with an obd scanner to determine the source of the issue and the potential repair necessary.