I had a similar situation, everything fine one day, then noticed the Oil pressure gauge going crazy.
I replace the oil sensor and all was well.
Here is a link from a different thread that shows where it is on a 2000 - hopefully it is the same. It was quite easy to replace - if you remove the oil filter and attack it from below.
Good Luck
Monday, January 19th, 2009 AT 12:50 PM