oil light was flashing, then it went off and on. Now is on most of the time.

What is your question?

I have been having this oil light problem for about 3 months. The car is running smoothly and very well. Starts quickly, have power and it doesn't stall. The problem is the oil light is on. The oil sensor switch was replaced but oil light still on. A local mechanic checked with a scanner and said that indicated a misfire, and may be the spark plugs and/or a coil or fuel injector need to be replaced. However, the engine is not vibrating or showing any sign of having any malfunction. Oil is new and to the right level. The car has 71000 miles. Don't know whom to trust for the repairs and how much would it cost. So far, local mechanics can't give me a fairly accurate estimate. What do you think?