Q: 02 Buick lesabre rotten egg smell engine light is on engine running too rich in bank 1

Hi there. In most cases, the rotten egg smell accompanied by an OBD-II trouble code that indicates a bank 1 or bank 2 lean issue is due to a worn out catalytic converter. The catalytic converter can also give off rotten egg smells if you are running too rich and the excessive fuel in the exhaust cannot be burned off completely and causes the rotten smell. You might want to have a professional mobile mechanic come to your location and complete a check engine light inspection, so they can download the stored error codes that are indicating the bank one error, and determine if this is a catalytic converter that needs to be replaced or something different.