Since the start of the STAR smog check program in 2014 smog technicians have been extra cautious when inspecting the catalytic converter for proper installation and type. Passing a vehicle with a catalytic converter not designed for the specific make, year, and model of the vehicle, in this case, a 2001 VW Jetta, can mean the smog station losings its STAR status. Losing STAR status can force a smog stations out of business. In the past this was not the case. Smog technician were still required to inspect the CAT for proper model and fit but many slipped through the cracks.
At this point your only recourse is to replace your 2001 VW Jetta's CAT with one which is California legal and designed specifically for your car.
