Please help solve my puzzle!

[JMBT]

My DOC inlet never goes over about 650oF and usually stays in the low 6's. Quick serve says 550-750 is fine. My SCR usually remains a bit under the DPF temps, but still gets well into the 1000's, also the SCR in and out are nearly the same which I was told means there is no clogging occurring.
Sometimes I get the feeling Cummins doesn't even really know how these systems are supposed to act. Especially when they roll over 500K.
Bulldozer2, I think I will pull mine each out and very, very carefully wipe them off with a dry cloth before I replace either of them without a code. Each time I have replaced either before it was prompted by a code. We'll see.....