Volkswagen: Mass airflow Sensor, mass airflow sensor, golf gls

Question
I have a 2000 Golf GLS TDI with 215,000 km
Over the last 2.5 years I have had the Mass airflow Sensor replaced about 12 times (it's in the shop again today). The engine diagnostics always says Mass Airflow problem.

Is there an underlying problem with my car or is there problems with the MASensors?

Regards  

Answer
does the car run generally flat? or does it seem to have turbo boost then loose it and not regain it until it is turned off then back on again? does the MAF sensor seem to cure it? the MAF sensors are generally the cause of running issues, and tend to have a limited life. However 12 times in two and a ahlf years or 215,000km seems to be too frequent. such things as cheap air filters, being a little rough with the air box, or even high flow air filters can dramatically shorten it's life span. If it is being replaced so often, then a genuine volkswagon one fitted at the main dealers may be a wise investment (a little more expensive but then covered by a 12 month volkswagon warranty and therefore should be free if it fails within 12 months)