Finally got to NAPA and bought some MAF sensor cleaner. Man was it ever a pain in the ass to get to the sensor on the 4Runner. Had to take the whole airbox off... And once I got there found that 1 of the 2 screws holding the sensor in place was missing.
Also went ahead and cleaned the MAF sensor on my Taco while I was at it. That was quite a bit easer to get to.
As an update, the light never went back on after we just put in some fuel injector cleaner, but since then I've cleaned the sensor and put in a tank of premium gas. Let's hope this will ward off any evil spirits.