Diesel's have no throttles, it's the fuel which is regulated, not the air intake. If your car is an early one like mine (99 T), unplugging the MAF will cause an engine light and will go into limp home mode.
Position sensor can be checked through OBD, although unlikely to be it. I would really whack it on OBD, even the cheap ones. When you floor it, does the MAF sensor not detect an increase in air mass?
Position sensor can be checked through OBD, although unlikely to be it. I would really whack it on OBD, even the cheap ones. When you floor it, does the MAF sensor not detect an increase in air mass?