Answer: Catalytic converters are a very important part of your vehicle’s exhaust system. They are responsible for controlling emissions and protecting passengers. If you didn’t have a catalytic converter or if it fails, your vehicle can release very harmful gases. Your exhaust system can release carbon monoxide, which is an odorless, poisonous gas that can be deadly; hydrocarbons, which are a major contributor to smog; and nitrogen oxides, which are contributors to smog as well as acid rain.