just to clarify, deleting the egr RAISES egt's. The egr is used to cool off combustion temps by recirculating exhaust gases through the intake. It's taking the place of fresh air fuel charge. The already burnt exhaust is cooler than a fresh/ new explosion. This is why the PCM commands more timing with egr on, to increase lost cylinder pressure (lost through the decrease in torque from the deluted a/f charge) and the cooler temps allow more ignition lead.