Just in case you didn't get your love letter from VW:
EMISSIONS SERVICE ACTION N7
1999-2002 Jetta, Golf and GTI with VR6 Engine Update Electronic Control Module (ECM) Software for Catalytic Converter Monitoring System
"The electronic control module (ECM) software for the catalytic converter monitoring system is too sensitive. This can cause the MIL to come on, and some vehicles may exceed Federal and/or California emissions standards. Also, in some cases this leads to unnecessary catalytic converter replacement."
Mike