mass air flow sensor.

That's not a valid OBD-II code. If you mean P0101, that would seem to indicate a failed MAF sensor(signal out of range for > 4.0 seconds).

Could be a dirty sensor, or bad wiring. I'd check the plug/wiring first and see if you find any damage to the wires near the plug. If not, I've had some success using brake cleaner on the wires of a 'hot wire' MAF sensor. There are several kinds of MAF sensors out there though, and without any specifics on which year/model you have it is hard to tell if cleaning will work or if you need to find another sensor.

Keep in mind that an OBD-II code indicates a problem being observed in a CIRCUIT, not necessarily a SENSOR.

Chris