[fredjacksonsan]

Could be the oil pump is failing, depending on the mileage. How many miles on the MGM? Alot of cars will have low oil pressure at high miles. I don't know about the codes.

Is the engine burning oil? How much over how many miles?

New or rebuilt engines can be had at places like Advance Auto Parts, or of course junkyards for do it yourself. If you wanted someone else to do the work, find an engine shop or other reputable business that will do the work - and give you some sort of guarantee.