If this sensor in the EGR valve crossover tube or intake plenum of your 2007.5 to 2026 Ram Cummins Turbo Diesel goes bad, the engine will run rough until it is replaced.
Cummins EGR Exhaust Gas Temperature Sensor
Cummins Part number 2872858 Replaces Mopar 68206021AA Quantity 2 used per engine. Pre and post EGR valve.