EMS Light intermittent - Air Mass Meter/breather pipe

[tusken]

I recently purchased an x reg 2001 a3 1.8 t sport, private sale.

the ems light came on the day after i bought it. it hadnt been on when i test drove it, when the rac checked it out, or when i drove it 50 miles home after i bought it. The light came on the following day.

i had it checked by the main dealer (yes, i know, mistake!) who plugged it in to vag com and said it was due to needing a new air mass meter , and a faulty breather pipe (sorry i didnt get the actual numerical codes). since this work was going to cost 300 inc labour at the dealer, i thought i would shop around.

before i got the work done, 3 days later, the light went out, and it stayed out for the next two weeks - driving it short journeys every day.

I did a 150 mile round trip this weekend - drove like a dream.
then on monday, EMS light comes back on again. Im now waiting to see if it goes out again like last time before i get a private audi specialist to do the work.

my questions are these:
1. the car drives well even when the light is on - any symptoms i should be noticing with those faults?
2. am i doing any damage to other engine parts/systems by my "lets just wait and see" method?
3. im sceptical about rushing into changing parts when the light goes on and off - reading these forums shows that it often isnt the first thing they change that fixes the EMS light problem. Any advice people can give on this? so how confident can i be that the error codes that come up, are the real problem? could it be the sensor?
4. forgive me, im not the greatest authority on cars - what does the air mass meter do? and the breather pipe?

thanks for your help in advance

[Boardboy]

Have a read here: http://www.autoshop101.com/forms/h34.pdf

Condensed version here: http://www.samarins.com/glossary/airflow_sensor.html

Try not to fall asleep!!

Regards Boardboy