Volkswagen: air mass meter, optimum ratio, air mass

Question
my 2001 Passat, just barely has a warranty left and I am being told that I need
an air mass meter, can you please describe the signs that this need to be
replaced.  I have had multiple issues with this vehicle and no one has mentioned
this before (trial and error??) gets very exensive and frustrating. is this a
warranty item??

Answer
The air mass meter is used by the engine computer to control the air to fuel ratio.  If it doesn't work, will not be able to calculate the optimum ratio.  You may see worse fuel economy, rough idle and stalling.  My opinion (note: opinion) is that it should be covered by the power train warranty and/or the emissions warranty.  VW may see it differently.  If they don't ask to talk to the area rep.