I just had a check engine light cleared. The diagnose found codes for long term fuel trim issues. Can anyone explain what that means. (2). the mass airflow meter was removed cleaned and reinstalled. The engine light has not come back on, was this just a quick fix or is this common?

 

Nothing is really common each situation is different and the cleaning alone may have solved your problem that tripped the check engine light.

For now don't worry about it but hang on to the code and if it doesn't come back on any time soon toss it away and be happy with your ride.