This code just popped up yesterday and I don't know what the heck it is?

mass air flow low frequency, check connections at mass air flow sensor, also check to see if screen has been punched, make sure it is still there, if the screen is missing, check to see if there is any material from air filter element or oil, if it is a k&n typpe filter, and make sure the sensor wires are clean. Have seen it a few times, more often than not, mas airflow has been replaced for this code at my dealership.

Yep, that code means your MAF frequency is below a set limit (around 10 Hz) so the PCM is declaring your MAF non-functional. Check fuses as well. You *could* simply have a blown fuse. If so you need to find out why.

Interesting, what would cause the fuse to blow?

A buddy of mine with an RX7 with an LS conversion had the same code not too long ago. All we did was unplug the MAF and take it off hte car, look it over and put it back in the car. We cleared the codes and the car now runs fine. I have no idea why the code came in on his car and could offer no help other than read the codes and clear them for him. I thought that maybe the wire had been dirty from oil filter too but we could see nothing.

BTW, the RX7 is a beast with the LS and the T56 trans. Crazy fast.

Code likely set due to loose connection.
You likely solved it by R & R.