Exhaust Emission Systems: Description: Notes

Several systems are used to control emission of pollutants. System usage depends on model, engine, and transmission combinations. Each system is designed to control a particular vehicle emission. In addition, specially calibrated carburetors, distributors, and modified combustion chambers are used with these systems.

NOTE: There are 2 light duty truck emission control standards classifications: Light Duty and Heavy Duty. Light Duty refers to vehicles up through 8, 500 lbs. GVW; Heavy Duty refers to vehicles over 8, 500 lbs. GVW.