2026 Ram 3500 Engine Problems

Purchased the truck new with 25 miles on it from the dealer. Within the first 2000 miles, I had a message pop up that said "Service Exhaust System See Dealer". I took it in to the dealer, they said it showed a random emission related code had popped up but was not currently active, so their recommendation was to clear it and see if it came back. Within a day, the message was back and tripped a check engine light. I also noticed after the first 1000 miles, my fuel mileage dropping off significantly around the time the "Service Exhaust System" message first appeared. (I went from 18-19 mpg average, to 12-14 mpg average, driving the same commute to and from work, in the same conditions.) I have noticed unusually high temperatures in the exhaust at times, excessive fuel consumption, excessive DEF consumption, and am concerned about the potential for damage to the DPF or DEF system. I took the truck to my local dealer for diagnosis and repairs. They called me to say that the problem had been traced to a faulty Exhaust Gas Temperature (EGT) control module that was malfunctioning and would need replaced. They then explained that the part was "restricted" by Stellantis/Ram, and was not something they could just order. That they would have to create a "STAR" case with Stellantis and get the part authorized/sent directly from Stellantis. I was also told that they would not receive any updates or communication back on STAR cases and that the part would just show up whenever it shows up, and they would let me know. Was told to drive the truck until the part came in, as they did not have any loaner vehicles available. From some online groups I am in for this series of truck, I found a couple other people with the same problem, who reported that the restricted control module is on backorder from STAR/Stellantis until at least mid-January.