Rotten egg smell inside BMW 320d?

A rotten egg smell in a BMW 320d typically indicates a problem with the catalytic converter or issues with the fuel system. This odor is often caused by the presence of hydrogen sulfide, which can result from incomplete combustion or a failing catalytic converter. It’s advisable to have the vehicle inspected by a qualified mechanic to diagnose the issue and prevent potential damage to the engine or exhaust system. Prompt attention can help ensure the vehicle operates efficiently and safely.