By drawing fresh air through the EGR valve, the system will compensate for the extra incoming volume of air. Since it is fresh air, instead of exhaust gas, it will create a slight lean condition, which will be compensated for by the o2 sensors adjusting the fuel trim.
So, if you want to disable the EGR system without creating a CEL, just put a filter on the pipe leading into the EGR valve from the exhaust manifold and block off the hole out of the manifold. Technically this doesn't actually disable the system. It simply allows it to draw in fresh, cooler air instead of hot exhaust gasses.
