EGT's are Exhaust gas temp. Important in diesels so you don't melt something.

In stock form the PCM will monitor and defuel if needed to keep you from hurting it.

Some of us, especially Stanley tow and tow heavy. So you have something else going on. Sounds like you might just have some moisture built up in your Charge air cooler (CAC). Making the motor work harder causing more air flow and allow it pick up the moisture. Having an occasional WOT is not a bad thing.

Those that tow heavy all the time have fewer problems because of the demand for air.