First, thanks to all who respond in advance.

My oil pressure gauge in stuck at max all the time. Cold start, warm start, driving, sitting, all the time no matter what.

Now I assume thetre is no actuall problem with the oil pump or the pressure. There are no leaks that I can see, smell, detect in any way.

So, I imagine that it is either the sensor or the sending unit.

Does this sound resonable to assume to all here?
If so, can anyone tell me where the 2 units are (sensor & sender) and how to replace or check. Pics. are worth a 1K words.

First thing I would do is disconnect the wire from the oil sending unit to see if your gauge goes back to zero. This would help isolate if it is the sender or the gauge itself. Unfortunately I am not sure where the oil sender is located though.

+ 1

Makes sense. But, I may try disconnecting the battery first. It may be just enough to kick start the sending unit. Good luck.

I had an issue with mine and just replaced it. It was about a $60 part and a quick DIY project.

Mine did the same just replaced the sender. I had my indy do it when they did the IMS. I heard its not hard to do, just search oil sender replacement.

on an '02 C4S the sender is in the back of the engine bay (farthest from you, when looking in from the rear) above the motor on the passenger side. It is a cylinder shaped unit with wires connecting to the top.

I had issues with mine where I would get a failure message on the the display, then it would kick in and start working again. I was able to clean all of the contacts / connectors and the issue went away. I found a DIY showing how to replace it, and I belive it was recomended to pull the tire, and wheel well liner to get at it easily. I was able to clean everything from inside the engine bay without pulling the wheel.

Do some searching and I am sure you will find threads with pics.