What is the primary function of the EGR system?

The primary function of the EGR (Exhaust Gas Recirculation) system is to reduce exhaust emissions. EGR works by recirculating a portion of the engine's exhaust back into the intake manifold, which leads to a reduction in nitrogen oxides (NOx) emissions. By introducing exhaust gases that are relatively low in oxygen, EGR helps to lower combustion temperatures, which is key in minimizing the production of NOx, a harmful pollutant that contributes to smog and acid rain.

This system is particularly important for meeting stringent environmental regulations aimed at limiting the pollutants released by vehicles. While the EGR system can have indirect effects on other aspects such as fuel efficiency or engine performance, its main design and purpose are centered around emissions control.