Because of the probe's thermal lag during acceleration, you can over-fuel on hard throttle and never know it. It is therefore necessary to utilize an exhaust pyrometer instrument capable of measuring exhaust manifold temperature upstream of the turbocharger. Under no circumstances should the exhaust manifold temperature exceed 1250 degrees Fahrenheit. Other outfits don't even give you the courtesy of a warning. Correct calibrations require engine design knowledge and a big budget commitment by the aftermarket manufacturer.
Guys buy diesels because they are rugged and go the distance.
Bottom line, Cummins diesel pickups have an engine life expectancy of 300-400K miles. We Git-Kit the Ford Power Stroke too.