What are the primary functions of a car's exhaust gas recirculation (EGR) system, and how does it reduce nitrogen oxide (NOx) emissions by recirculating a portion of exhaust gases back into the engine's intake manifold to lower combustion temperatures and reduce the formation of harmful pollutants?

The primary function of a car’s exhaust gas recirculation (EGR) system is to reduce nitrogen oxide (NOx) emissions by recirculating a portion of exhaust gases back into the engine’s intake manifold. By reintroducing inert exhaust gases into the combustion chamber, the EGR system lowers peak combustion temperatures and reduces the availability of oxygen, inhibiting the formation of NOx pollutants. This helps vehicles comply with emission regulations while minimizing the impact on engine performance and efficiency.