DOC Catalyst Efficiency Numbers

[Rawze]

According to some documents I have on the after-treatment system, if the system thinks the "Estimated SCR Catalyst efficiency" is too low, it will do additional regen because it thinks the decomp tube might be partially clogged up/dirty.

Pull the DOC and DPF, have them cleaned, baked, de-ashed, and flow tested. Do an EGR tune-up on the engine, and Check the decamp tube for the all too familiar "Volcano" scenario mentioned here...
http://rawze.com/forums/showthread.php?t...07#pid1807

clean the DEF screen and injector while your at it.

As well, like has been mentioned, take pics of the faces of the DOC and DPF and post them here for some opinions on what may be built up on their faces.

Also, like mentioned, check for white smoke or other liquid spatters when starting up the engine with a piece of paper held right behind the turbo/doser pipe and the exhaust pulled loose.