Q: My car failed inspection with P0420 and P0411 codes 2005 VW Jetta

Hi there - the P0420 indicates a catalytic converter that is not working as efficiently as it should. This could mean a clogged converter, or weak oxygen sensor (probably the pre-converter O2 sensor). The P0411 code indicates a secondary air injection pump "low flow" problem. This pump injects air into the exhaust to complete combustion of unburned fuel. The message indicates the pump is not providing the expected amount of air. This could be due to a weak or worn pump, or clogged air filter for the pump. I would recommend an exhaust and emissions inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.