Pending DTC, no Cel on Maxxforce 13

Trying to figure out a pending DTC (but have no warning lights) which I picked up in NED. The code is: SPN 4766 FMI 02, DOC Outlet temp. signal erratic, intermittent or incorrect.
Is this wiring issue or faulty sensor, anybody knows what else can be done to diagnose it?
Also, noticed a percentage difference in reading for O2S
O2S actual 15.xx%
O2S desired 5.xx% (see attached pic)
Any idea what that difference may be indicating?
Thanks in advance

 

And now threw a Cel
Also my transmission temperature guage is going nuts, it fluctuate anywhere between 120 deg. and 250deg.
I think i have connection issues in the wiring and/or plugs due to nasty weather last week. Truck got fair amount of salt bathing past week for a few days. Parked on Saturday last weekend and Monday issues appeared out of nowhere. I personally hate to deal with electrical crap, I'd rather deal with bolts and nuts

 

Thanks for heads up Heavyd, this afternoon I was able to run my newly acquired NED software, the code was in "healing status" and been able to clear the code no problem. After that I disconnected all 4 sensor plugs at the dpf/doc, cleaned (although they were fine except for one which had slight corrosion build up, not significant though) lubricated pins and put everything together, fingers crossed everything seems fine. Also ran aftertreatment test and it came out excellent with soot at 10%

Also ran a DLB software and pulled some codes but I won't bother you with them, unless I can't solve them myself.

Are you able to check out the service history by Vin #CN620725?
I'd appreciate that very much, Jacob

 

Awesome info, exactly what I was suspecting. Hats off to you my friend.
Would you happen to know what could be a problem with both mirror heat not working while power mirrors do work just fine. I'm throwing code for heat undercurrent or relay, would you be able to point me in the right direction here or give me a starting point. Thanks in advance, Jacob

 

Heavyd, thanks for taking the time to read/respond. I really do appreciate it.
I'll take the covers off and inspect the wiring/heating elements for corrosion/voltage. That at least gives me a common sense option before serious dig into electrical, which I'm not excited about whatsoever.
Thanks brother and enjoy your day