New here guys and new to the Diesel scene so my knowledge isn't the best. However I am not a Dodge owner I am a Ford owner so go easy on me, I come in peace. I'm here on my Moms behalf since she doesn't understand the internet and forums like these. She drives a 2015 2500 Diesel. Over the last 4 months she has received a warning light and had to take the truck in to the dealer to replace the Cat Converter. I didn't know diesels had these, thought it was the SCR. Anyway, now she is getting the warning again and this time it is saying not to exceed 5 mph and to check the DEF level. She says the DEF is a little over half. Is there an ongoing issue with these converters or does anyone know the fix. It seems to me the dealership is not checking to find the root cause, they are just reading the code and blindly replacing the converter without checking for other issues. She using the truck 2 to 3 times a month to pull a gooseneck horse trailer for a few hours one way. Other than that normal everyday truck if that matters. Thanks for any help.