SPN-402942 ? I can't find this code listed anywhere

2012 VNL D11 700k miles

I'm having SPN-4094 (nox limits exceeded) issues that come and go. If I drive long enough it will clear and remove the derate. And then usually the same day or next day I'll get derated again. One code that has shown up in Motive is a few of these 6 digit SPN codes. I can't find any information on them anywhere. I have had up to 6 or 7 of these codes at once. The current one I have is SPN-402942 FMI 9

I also had two codes for open circuit on the EGR temp and EGR differential pressure sensor. I had my engine wiring harness replaced last year so I have a hard time thinking its a wiring issue. So today I replaced those and also the boost sensor also.

Other than the bolt on the frame rail behind the batteries are there any other ground points I should be looking checking/cleaning? I have also replaced the DEF doser valve which has not helped. I also removed and cleaned the Venturi tube in an ultrasonic cleaner (it wasn't that dirty)

any thoughts and opinions will be most helpful!