I bought my 01' Audi a4 quattro 2.8L in September 07. I have been experiencing a few codes lately that has held me back from getting my ride inspected. These codes are probably robbing me of horsepower and torque but I'm not sure. I've had these codes for a while and I'm not sure what to do in order to fix it.

PO 420- Catalyst Efficiency below threshold (Bank 1)
PO 430- Catalyst Efficiency below threshold (Bank 2)
PO 441- EVAP Emission Control System Purge Flow Fault

When I fail my inspections, the Catalyst, Secondary System, and Evaporative System are not completed.
Lately when I've been driving 20-25, 30-35, 40-45, 50-55 it misses. It kind of feels like a spark plug issue but I'm not sure. Hopefully it's not my c. converter.

Any help is much appreciated!