Oil sensor intermittent

Not very likely as the engine oil and headlights share nothing. I would first check the oil level just to be sure it is full of oil. Then look in the area that the work was done to see if perhaps they moved the wiring. There should be both oil level and oil pressure sensors on that car and I would expect both to come on as a warning if the oil being low caused a problem. It could easily be a failing oil pressure sensor but without a scan tool to read it you cannot do a lot unless it is in the failure mode. The shop or dealer can connect up and test much easier and tell you what they find.