I was wondering if anyone could tell me some signs of maf sensor going bad. Can it still be bad if my check engine lite doesn't come on?

 

there are very few instances where the maf was bad and it did not illuminate the cel. there are more occurences when the maf is dirty from oil where it is cleaned and some hesistation and stumbling goes away. if the bad if shot, then you will not be able to rev over around 2.5k rmps. if you have hesitating and stumbling then you want to consider cleaning it with electronic parts cleaner. some have used intake or carb cleaner but i am not sure if it safe for the plastic surrounding the maf wire or not.