I would just check dipstick regularly until you go past a Mazda Dealer - go in and ask for the parts manager - he will know where to look and probably have a replacement as well.

Now Pipes, you should know where it is, you may not have seen it for a while, but it should be right where you last left it.

I've been doing a bit of research Most, but not all, oil pressure sensors are located near to the oil filter housing. another site said next to A/C housing. Your engine is built with an advanced network of electronic devices; perpetually relaying the operational status of each system to the engine control unit. A principal component of this network on your Mazda MPV engine is the oil pressure sender and switch. More than just a sensor that illuminates a light on your dash, your Mazda MPV oil pressure sender transmits data to the ECU that it uses to adjust how other components perform. If you discover that your oil pressure switch has failed, don't treat it lightly.

Discount parts www.carpartsdiscount.com/oil-pressure-sender-switch/mazda~mpv.html?3594=2358

Sorry that's about all I could readily locate - If you can't find it you may need to see your Mazda Dealer as I said previously.

Thanks Possum 3. I will check it all out. However, my engine is a Japanese version of the well known Perkins diesel. (1991) 310000 klms, and still running perfectly.
Regards.
Pipes.