Thermostat

What is your question?

My jeep's check engine light recently came on and around the same time I notice that the running temperature dropped? It is normally right under 210 degrees and now it is around 150 degrees. I would go and get the check engine light checked at a parts store like a normal state. l but I live in the "DAMNED STATE OF CALIFORNIA " were they do not check engine lights unless they charge you an arm and a leg (Some Environmentalist BS) Getting back to the question what should I do?