Anyone see these before?

P0172
P1101
P0496

All these at once came up on me. I did a little research and I'm guessing it could be something as simple as a dirty maf. I cleared them and they haven't come back, which is a good thing. But I'm looking to see if there's anything I should do to prevent these from coming back.

Thoughts and or experiances?

 

did u add any fuel additives such as lucus or octane booster???? thats what caused my rich condiotion

 

p0172 = rich fuel trim
p0496 = Evaporative emission system high purge flow
p1101 = mass airflow sensor out of self test range

my guess is the maf needs tuned.