re:  I failed emissions:( and I need to fix something so that I can
get
it to pass. Suggestions?

Obvious suggestion is to take it to mechanic familiar with VW.  If
your O2 sensor is old, it's pretty cheap to just replace it yourself
on speculation it might help.  Better than paying a mechanic to do
it.  Beyond that, most of this is beyond home repair.  Could be air
mass sensor, which will be big bucks.