Audi A4 is one of the most sought-after entry-level luxury sedans in the world. Your Audi A4 comes equipped with many advanced features that play a crucial role in the smooth running and better performance of the car. However, drivers have often complained about the malfunctioning catalytic converter in their car. The catalytic converter is an important part of the emissions control system in your Audi. Go through the video to know the top 5 Audi A4 catalytic converter problems.