Engine Mechanical problem
2002 Volkswagen GTI 4 cyl Two Wheel Drive Automatic 85000 miles

hi i have a 2002 vw gti.. with the turbo...recently the check engine light came on and they told me that it was the mass airflow sensor was the cause cause i wasn gettin really bad gas mileage and as well as my car didn turn on 1nce.. so my brother who is a mechanic changed it for me.. the light is still on and it has been almost a week now??..he told me that the car has to go with cycles to turn off the light but i would like to knw if maybe i was supposed to do something else maybe program the mass aiflow sensor or somethingg??..please help..