The EGT probe is a sensor that allows users to monitor critical Exhaust Gas Temperatures to ensure added power is not creating excessive heat which, in turn, can cause engine damage. This kit is ideal for the daily diesel driver or if you are towing then it's a must have! Towing can put a lot of strain on the truck and make it run hot. Don't be left on the side of the road with an overheated truck because you didn't watch your Exhaust Gas Temperatures with the Edge EAS EGT.