1. • Raw fuel is primarily made up of Hydrocarbons (HC).
• Should be almost completely broken apart by the
• If there is a lack of combustion (misfire), some of the
Hydrocarbons pass through unburned and out the
• Variations in the combustion event (imperfect
combustion) allow HC’s to pass through unburned.
• Catalytic Converter can only deal with a normal
amount of HC’s.