Which part of the vehicle is not directly inspected for emissions?

The suspension system is not directly inspected for emissions because it is primarily responsible for providing vehicle stability, handling, and ride comfort. Emissions inspections focus on components that affect the vehicle's emissions output, including systems that manage the combustion process and the disposal of exhaust gasses. While the exhaust system, fuel system, and engine performance all play critical roles in determining how much pollution a vehicle emits, the suspension system does not influence emissions levels. Therefore, it is outside the scope of what is measured during an emissions inspection.