[200q20v] alternator replaced, stereo fuzziness gone, stalling

[Vztante at aol.com]

Hi all,

After having the alternator replaced a week ago, the static/fuzziness that I 
used to hear through the radio during throttle input is completely gone! 

On the other hand, the car now stalls once every other time I take it out, 
usually after coming off of boost, or coming to a stop.  I wonder if the idle 
may be set too low.  It seems to have a tendency to dip below the usual rpm 
as I come to a stop.

Mitch Frey
'00 A6 2.7t
'91 200tq20v IA Stage 3