A look into the exhaust gas recirculation, or EGR, valve - an important piece of the automotive emissions system.

Exhaust Gas Recirculation (EGR) valve is a critical part of modern diesel and gasoline engines since it regulates emissions and reduces nitrogen oxides (NOx).

In Part 1, I regaled you all with the brief history behind the discovery of photochemical smog, and then proceeded to dazzle ...