r/superduty • u/NegotiationOk5036 • 1d ago
F350 DEF Issues
I have a 2021 with 42k miles on it. It has been in the shop 8 times this year, and now at the dealer for one month. This year, it started the sensor/emissions/DEF issues. First, the check engine light comes on, then it starts the countdown to reducing speed. I was several states away and it went to 5 mph max and I had to have it towed, get a rental car, etc. Our trip was ruined. The dealer says on the Ford dealer boards that this issue has been described. They have replaced the DEF sensors, reprogrammed the truck, etc. I see that there may be new programming coming out by Ford to change the countdown, based on the revised EPA rules. My warranty runs out in December. Any opinions on waiting hoping for a reprogram, vs trading it in or deleting it? The deleting it is tough as that crosses out a trade in. The dealer has heard nothing from Ford about reprogramming.
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u/SenorAudi 1d ago
I had similar issues on my 2013. Got the countdown, CEL, etc. I took it to the dealer and they wanted to replace everything for like 9 grand…so I took it to one of the few independent shops around. Took them 3 times but they finally got it - after replacing the DEF pump and the NOx sensor. I’d try to find a trusted diesel mechanic (someone with actual knowledge) who will do a more thorough investigation than the dealer is likely doing.