What mechanical components exist on today's fossil fuel based cars that help prevent air pollution?

Answer 1

The only mechanical component to hold down polution from fossil fuel burning cars is the catalitic converter.

Answer 2

Some mechanical components on fossil fuel cars that help prevent air pollution include catalytic converters, which reduce harmful emissions by converting them into less harmful gases, and exhaust gas recirculation systems, which help reduce nitrogen oxide emissions by recirculating exhaust gases back into the combustion chamber. Additionally, fuel injection systems help optimize fuel combustion for improved efficiency and reduced emissions.