I detect a sulfuric smell coming from the catalytic converter.
Hi there. The smell of rotten eggs is due to a compound called hydrogen sulfide. This comes from the small amount of sulfur that is present in the fuel. Normally, the sulfur is converted to sulfur dioxide, which has no odor. When the converter breaks or the filtering layers have worn down inside the converter, the sulfur is not transformed into the odorless form. Therefore, a strong rotten egg smell is produced. Another possible cause for this smell may be that the converter is plugged. Unfortunately, you cannot repair it, which means you need to have the converter completely replaced. I would have a technician from your mechanic replace the catalytic converter to get rid of the smell.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%