Here you go... more than you ever wanted to know about the MAF on these cars:
http://sites.google.com/site/mikefocke2/checkenginelightcausedbymassairflowsensor
Included are instructions for cleaning or replacing it. I tried the cleaning but it was a temporary fix. Replacing the MAF solved all hesitation issues with my car. To test it just unplug the MAF and drive the car. If it runs better, replace with the proper part# for your model and year.
Also review the work areas around your alternator and fuel pump. It is possible that something got knocked loose or was left undone causing a vacuum leak. These cars run best with no intake vacuum leaks.