Are you sure you have a legitimate problem, or is it imaginary? Is the CEL
(Check Engine Light) coming on? My owner's manual says that it's normal for
the Oil Pressure light to come on at low idle speeds when stopped. My Haynes
manual says that normal oil pressure is 10 PSI at 500 rpm and 30-55 psi at
2000 rpm, and I know my '96 Rodeo 3.2L V6 runs really low oil pressures.
Like you, I was worried when I first bought it because of the ridiculously
high end of the oil pressure gauge (215 PSI). I thought that it should
probably run somewhere in the middle to be normal, but not so. To cure my
anxieties, I changed to a higher viscosity oil (50W) and that brought the
pressure up a bit.
I simply quit worrying about it. That took care of the problem.