The engine is low on power, and the check engine light is on.

Loss of power, engine light on. Two months ago, the car went into limp mode, and the customer limped into a nearby garage. They changed the mass airflow sensor. It was fine for a month, then the same thing happened. The customer went to a different garage, which also replaced the mass airflow sensor. That only lasted a week, and the car has done the same thing.