Catalytic converters

[Timstrk]

On a full cab or enclosed full size the exhaust exits the side of the vehicle. That way is doesn't get trapped in the low pressure area directly behind the vehicle. This would cause it to come into the cab where you could smell it. Out the side goes with the airflow past the vehicle. A catalytic converter burns unspent fuel from the combustion cycle in the engine. If you are running rich you would set yourself on fire because the converter gets very hot burning the unspent fuel.

Tim