The IAT sensor works in conjunction with others(sensors) to determine A/F ratios, the O2 monitors oxygen in the exhaust stream and also helps to correct A/F,so these are related in purpose and share circuitry.

The EGR valve also gets feedback from the O2 sensor via the ECM that tells it how much O2 is in the exhaust stream and helps determine when to open and close.

I am not familiar with the temp sensor diff sensor for CIS and EZL, except the CIS is, as we know, the injection system, and EZL is part of the ignition system.

So we see that all of these codes are related to sensors that monitor A/F and programed parameters for engine temperature.

One would suggest checking each of these sensors individually and see what results are found, theorectically, one bad sensor may have caused the others to operate out of range and thus set a code.

Good luck, have fun.