01 rio with p0101 code

I have a 2001 rio that keeps giving me the code p0101 after the check engine light comes on.I know it indicates that the mass air flow sensor is maybe bad so i replaced it with a new one.
2 days after i replaced it the light went out and stayed out for a week and now back on giving the same code p0101.

anyone have any idea's what may be going on?thanks