Please help solve my puzzle!

[JMBT]

Kenworth2012, thanks for the reply.. Yes I think quick serve, insite, and Rawze are the way to go! Mine has been in the shop only once since new, and I now have 550K. The core charge on the NOX sensors must be new. I bought my last one 100K ago at a freight liner in Atlanta no core at that time. $400 for the 3 ft model, which both of mine happen to be. The shorter lead models (2ft and 1ft) were cheaper of course.
You are correct the inlet should be higher then the outlet, in the above post I just stated in backwards. During the regen mine were reversed, (inlet low, outlet high), then after the catalyst cooled back down to normal they switched back to normal or proper (inlet high, outlet low).
Billdozer2, I don't know for sure where the NOX numbers should be, but at high idle I am around 150 on the in and 30 to 40 on the out...I would guess the lower on the out the better!! If you are at 389K and never changed one of the NOX sensors you are doing great!! I changed my first one at 188K, and then there were more to follow.
I second Kenworth2012 on the DESA test, but be prepared it can run your motor at 1700 RPM for up to 10 mins while it is diagnosing. Not bad, just hard to listen to if you normally run your motor easy. I used to mine purring along at 1450.
By the way what kind of temps are you guys seeming during regen in the SCR? Just curious to see how they compare to mine.