The MAF is strictly to monitor/validate EGR. As far as I can tell...
You have a few choices for a fix:
1. Replace the entire sensor - $$$$
2. Replace the sensor insert with one from a Volkswagen - $$
3. Clean it and hope for the best - $
4. Do my MAF elimination circuit - <$
Elimination circuit involves a 22k resistor or some such value. It's been so long since it was discussed, I don't remember know. There is a dedicated thread for MAF elimination though.