Hi djbock. Welcome to the forum. Run the engine for a bit with the sending unit disconnected and see what the gauge reads. I would hope you find it's still high due to a wire rubbed through making a high resistance short to ground. 200 psi should explode the oil filter, so I would like to think the pressure isn't really that high. As an alternative, what does the gauge read with the engine stopped and the ignition switch on? Naturally it SHOULD be 0 psi.
If the reading goes to 0 psi with the engine off or sending unit disconnected, that would rule out a grounded wire. Normally I'd suggest having the pressure checked with a mechanical gauge, but the likelihood of two sending units being defective is unlikely so they will probably be in agreement with the mechanical gauge.
If everything points to the pressure really being that high, suspect a blocked pressure relief valve in the oil pump, either from debris blocking the port or corrosion causing the valve to stick.
Tuesday, May 11th, 2010 AT 1:15 PM