Got it. I'm replacing the oil pressure sensor this week - drove the car some and no adverse changes. If the problem continues after the sensor is replaced, I'll be doing the wrench turning myself and will need a good shop manual on the 2012 Mazda engine. Any recommendations?

Thank you again for your inputs. I didn't know that about the hot and cold radiator tanks. Coolant on this engine seems to be OK - no issues noted. I'm going to change the oil pressure sensor this week and see what effect it has. Drove this weekend with no changes. Oil pressure sensor light continues to go off when engine increases to 750 or so RPM's. Never comes on until engine is at full idle. If issues beyond this, I'll be turning the wrenches to deal with the problem. Any shop manual recommendations?

Hmmm, sounds like an old tired engine.

You perhaps might know where the oil pressure sensor is located or have a diagram of the engine with its location? I have the replacement sensor but cannot find its location? I thought it was on the drivers side of the engine wall?

Front of engine, down behind the radiator fans.
https://cimg2.ibsrv.net/gimg/www.maz...4ab756312d.png

Perfect - found it - but what a screwy location. Old one is looking very shabby. Need a couple of tools to get at it and will put in the new on tomorrow.. Many thank for your help.

Just wanted to mention in conclusion that the oil pressure light is off. Thanks to everyone who responded!

any chance of advice on how you found the sensor and what it took to get to it?

Stand in front center of the engine bay - the sensor is straight down, way down at the at the front and bottom of the engine - facing towards the front of the car. There is not alot of room to work with - having smaller arms and hands will help enormously as there is only a smaller space to work with between the engine and radiator assembly. I did not want to take off the radiator fans etc. unless I really needed to. I recall needing a 21 mm deep socket and a very long 3/8ths extension with a universal socket holder so that the wrench could swevle in any direction unimpeded. I tried only to use the socket to initially loosen and then finally tighten the sensor onto the engine. I removed the plastic under-car protector in the very front so that I could get at the sensor wires from under the car. I worked the wire connector off from both the top and the bottom of the engine - and also assisted putting the wrench on the sensor from under the car. Placing the deep socket on the sensor, I turned it loose and was able to back it off by hand. I guess I was lucky that there was not alot of road dirt in around the sensor. Once the old sensor was removed, I manually screwed in the new sensor by hand from above and underneath the car - then used the 21 mm deep socket to tighten the sensor in place. The finally put the wiring onto the new sensor. Oh, and my wife helped enormously while I was under the car working the sensor wires loose, as she provided direction to me in relation to the sensor location from above. And, at the beginning of the repair, I removed the negative battery connection and reconnected it at the conclusion of the repair. The computer must have identified the change as the oil light went out after restarting the car.

In my description above, I left out the times that I cursed the engineers of various companys who thought to place the sensor in this position on the engine and with no room to work with to change it - it was a combination of Ford (engine) and Mazda (chasis etc.) directed expletives. Hope this helps!

Low oil pressure warning at idle
 

I had same problem it is due to faulty electronic pressure sensor just replaced it and it's gone.