Also, sometimes my idle sits at 1500 RPM, and sometimes it idles normal, which also, to me, points to a vacuum leak, but Im not sure.

 

There's a good chance you need a new one of these;

http://www.mazdatrix.com/boil2.htm

- Scroll down to Oil Sender Condenser.

I just got one from Mazda about 3 months ago. I had the exact same problem. It wasn't caused by a popped hose, but the whole funky oil pressure gauge thing was happening. It costed about $15 IIRC and it fixed it right up. It's worth a shot anyways.

 

Man, no longer available! That is the part that was getting sprayed directly with coolant, so your probably right. Know of any other sources for that?

 

I got mine from the Mazda dealership. If they don't have it at the US dealerships, I could buy on up north and ship if you're interested.

 

Replaced the oil pressure sender unit with one from mazdatrix and it's a perfect 60psi now! Just have to track down the random high idle problem now.