MX13 SCR downstream sensors

Hi, I have a 2016 MX13 . My system is split. DPF on passenger side , SCR on driver side. There are 2 sensors at exhaust outlet. The DS nox and right across from it a sensor with a bigger nut , not 22mm like nox. This sensor is broke. Slopping around in the nut . Problem is no one seems to know what it is

 

I found out it was the PM. It is not actually the threads. The nut part of sensor is screwed in tight. It is the sensor totally loose in it's nut. But no faults showing so I guess it still works.
I finally got the nox out. Had to take a torch to it to loosen it up. Was going to clean it and put back in but decided it was probably the controller bad so I bought a dorman 904-6006 to replace it. Hope it works well. About half the price of paccar.

 

I would have done that through my warranty but since rush in OKC kept my truck for 5 weeks just to put 2 wiring harnesses in, I'm flat broke. Needed to get to work. No time for more repair shops and warranty waiting crap. So I went the cheaper route. I can always have warranty pay for another one if dorman dies out.

 

Weird stuff. The dorman is actually wired 180 off from original. Had to twist the plug around to plug it in. It did work though. But I'm getting weird mpg. Changes every day. Bobtail 7.8. next day 5.5. today 8.8. used to get around 11.
Hope it don't drop too much when I hook up trailer.