SPN 4364 FMI 17 cleared on its own!

On my 2020 Cascadia I had the MIL light come after about sixty miles after I had filed up diesel as well as DEF. I ended up having the fault code SPN 4364 FMI 17. Truck had 510,000 miles when the code popped up. Both inlet and outlet NOx sensors were replaced at 477K miles, so I was wishing there wasn’t a problem with those. I bought this 2020 Cascadia back in April 2024 with 460K miles. I thought the code popped up due to either poor DEF quality or a clogged up DEF filter. I haven’t changed the DEF filter yet, but I will be getting it replaced soon. I did a forced regen a little later at 510,047 miles, but the fault didn’t clear up. That next day I had purchased two bottles of RiSLONE DEF Crystal Clean solution that I think would have helped out, but I was going to wait until the DEF got to at least half a tank. To my surprise, later that day the MIL turned off around 510,700 miles and hasn’t shown up since. I wasn’t sure if I just got bad DEF from my fuel stop, or maybe due to crystals that had built up inside the tank. Either way, I did end up adding two bottles of RiSLONE DEF solution at around 511,800 miles.

I don’t know if anyone has gotten this fault code and what their experience has been? Do any of you truckers buy boxed DEF instead of bulk? Do you think this RiSLONE DEF Crystal Clean solution is actually worth it?

 

I greatly appreciate the info. Hopefully my truck is shooting the proper amount of DEF and hopefully don’t have to spend a ton on repairs if I get other codes related to it.

 

Thanks. I’ve been using Lucas products like the DPF Diesel Deep Clean for a couple of months now and I just used the Lucas Cetane Booster. I do feel the difference in power and fuel economy, but I’ll be checking out those Hot Shot products.