We use 2020 and 2021 Ram 3500 for car haulers, we have a 2020 that was bought in July and has spent 9 months in shop and 2 out. We just got it back and made it 700 miles before the exhaust filter warning started againand limp mode. Stopped at two Dealerships to have it checked between Billings MT and Lubbock TX and no problem detected by dealer. We are now dead in the hiway 60 miles fro Lubbock TX.