I could find any answers in this thread I have 2015 Freightliner Cascadia evolution dd15 dt12 when I bought the truck dealer told me they baked the dpf filters and put it back after about 10k miles I got check engine light came on and I got this code spn 4364 fmi 18 I took it to TA tech hook up computer and checked the codes and said the soot level was not reset so he reset the code did force regen all codes clear after about 2k miles same code popped up spn 4364 fmi 18 I tookthe truck FL dealer and this time they told me it was my out temp sensor was not properly connected codes clear drove maybe 700 miles got same code again this time my def lights flashing I did park Regen whish I could do all codes clear exept mil light was on I took it to my mechanic he replaced out nox sensor cleaned def doser all clear drove truck few hundred miles check engine light came on again no codes and it said on for while then turn off could it be because the dealership did not change seal and new brakets
4364 fmi 18 is a catch all code for low NOx conversion. It can be many different things causing it. Generally the DPF filter is NOT one of them. It has more to do with DEF fluid quality, SCR efficiency, DEF pump, NOx sensors. How many miles are on the truck? If you are pushing 700,000 miles the SCR could be wearing out. If that were the case, the entire One-Box may need to be replaced.
The truck got 488k miles from what I can tell looks like bunch of new parts where replaced. New EGR, new coolent pump, new turbo pipes, ECT and I forgot to mention the computer showed something like permanent nox conversation efficiency low I don't remember if it said scr
