High EGT......HELP!!!!

[in2trux]

That's a nice looking rig. The small trucks these days come wth big truck price tags.
At 215,000 miles÷ 7624 hours gives you a lifetime average of 28.2 mph.
Those are the the same numbers I see running NYC area, lots of idle time sitting in traffic.
Very hard on the emissions system so periodically doing a forced regen can help keep the filter from plugging.
Oil takes a beating under those conditions so you might consider going to an hour interval change instead of mileage and getting a bypass filter on it asap.

You say aftermarket DPF, that could be a source of problems too. Did they do a reset in aftertreatment maintenence when it was installed? Just thinking out loud.