The Hated EGR Valve Discussion......

EGR reduces cylinder temperature by diluting the oxygen intake and therefore causing the combustion process to be cooler so the thermal NOx formation is retarded. (think of a air bellows in a blacksmiths furnace, more oxygen, more heat, more Nox) It only forms at temps above 2500F so if you can keep the process under 2500 by reducing the O2 in the air/fuel intake, then you reduce NOx formation. Wanna make your NOx go through the roof? Remove the EGR, plug it, or add O2 (lean it out). My truck passed with almost failing NOx levels. I cleaned the EGR and more importantly, the tube that feeds it from the exhaust. It was very restricted with carbon. as for more midrange power, Im from Missouri, show me. EGR in a camper or motorhome probably just keeps the motor cooler.