I think # 4 is the one up top. you can witch all 4 at the same time to be sure witch one gets the hottest when you push it. I deleted so I have mine up top in the delete plate.
that's why your mileage is low it most likely never completes the regen I know around town once it goes into regen I would have to drive 10-12 miles for it to complete. :(
Yea with all that weight it most likely stays in the 6-7000 range on the exhaust temp side. I know when I pull my 3 horse trailer loaded for camping My dpf % stays about the same . And the temps are 6-700 on sensor 1
if you want egt reading get an edge insight It is only a gauge so no warranty troubles It reads what the comport sees. there are 4 egt seniors and you can read up to 9 things at a time it will also let you know when you’re in and out of the regen crap.