I see it's a common problem, in my case it occurs totally randomly, sometimes the gauge will just spaz out for a sec or two. Most drive cycles it doesn't do it at all.

Is there any way to I test whether it is the sensor, the gauge, or the camshaft synchronizer?

 

Just replace the oil switch on the engine, its not a "sensor" its just an on/off switch that grounds the oil gauge when oil pressure is above 5psi
Assuming your Ranger is 1989 to 2011

If its a 2 wire switch test that one wire is a good ground, usually black with stripe wire
If you ground the other wire and turn key on oil pressure should show in "normal" range, than means wire to gauge is OK

If its a 1 wire switch(pre-1995 or so) then do NOT use tape on the threads when installing the new switch, it needs a GOOD GROUND to the engine

You would hear Valve Train noise if oil pressure was actually dropping below 4psi

 

Some people have said the issue isn't with the switch but the gauge and I was wondering if there was a way to test before just replacing part, but I guess the switch is cheap enough to swap out, and if it doesn't fix it, it doesn't hurt having a new switch.

I am occasionally hearing a "chirping" noise, but so far it has been when it was wet outside and I don't know if it is a squeaky belt or the camshaft synchro

 

Yes, switch is cheapest and really the only test
Ground the wire at the switch and see if gauge is steady, key on, engine off
If not then its a problem in the instrument cluster, extreme long shot

 

Yeah the challenge is the problem is really intermittent. I was driving the truck all over today hauling **** from Lowes back to my place, and the guage never wavered for a second, not once.

I'll replace the sensor and see what happens. My only worry i potential cam synchronizer

 

Cam synchro is a monitored device, it will set codes and turn on CEL(check engine light) at the slightest sign of a problem
Oil pressure is NOT a monitored system

So in the absence of codes and CEL, its not Cam synchro issue