I had the reflash completed on my truck yesterday (Thursday). Today Friday I drove 300 miles with no load. I do have a pyrometer and boost gauge. If I didn,t have the pyro. I would not know when the regen cycle takes place. The one thing I am concerned about is the 1200 degrees I am showing while in regen. What would it be if I was towing my 35ft. 5th wheel trailer? Anyway, this is what I observed today while driving the 300 miles. The truck would go into regen after driving 65 miles. Regen would last approx. 10 minutes. While in regen the pyro temp. holds 1200 degrees unless I ease off the gas. Holding a steady throttle temp. stays at 1200 degrees. I would recommend a pyrometer for the 6. 7 liter engine. I have not pulled my trailer yet but, I am concerned about high pyro temp. When not in regen mode the pyro temp. run between 600 to 900 degrees. I would like to hear from people that have pulled their trailers to hear what temp the pyro is showing. I read where one guy was showing 1500 degrees while towing a toy hauler. This high of a temp has got to cause damage.
Jim, you do not give us an important parameter,... what is your driving-speed? If you are driving at "highway speeds", I would be very surprised if active regen was required as-often, or for as-long, as you report. (You also need to positively verify WHICH flash you got. I assume you mean the "REV. A" re-flash. )
For comparison, my nearly empty 3500 dually, with the "Rev. A" flash, gave ZERO high-temp indications of "active regeneration", while driving 754 miles at varying, but mostly 55-75-ish speeds. This is as expected, because at these speeds and their associated exhaust temps, "passive" regeneration should suffice (as described by Cummins). Passive regen should not show increased readings on the gauge. It is accomplished continually, as a matter of course, when exhaust temps are adequate from normal running conditions (In Cummins' terms, the process is "transparent" to the driver. ).
The only regen-associated "heat rise" comes when "active" regen introduces raw fuel into the DOC, specifically TO CAUSE a temporary temp increase to required levels. This should only happen if normal temps while running are too low for regeneration, and a soot build-up (or some function of the sensors mentioned below) triggers active regen.
Although I might have missed a momentary occurence, the only way I was able to see temps in the 1200 deg. range, even briefly, was when I deliberately "pushed" the truck on an uphill run. (My EGT sensor is installed pre-turbo,... where is yours?)
It is possible that the 3 (fACTORY)exhaust gas temp sensors and the 3 oxygen sensors associated with the system have some influence on the initiation of active regen, aside from the pressure-differential switch which tells the ECM of soot build-up/obstruction.
So far I have not found a full explanation of their function.
But in any case, either your rig is showing unusual A-R frequency (for highway speeds) or mine is on its way to serious clogging. My case seems to better represent operation as intended/explained by Cummins.
FWIW, BBeck reported similar frequency/ high-temperatures during his first miles driven w/o the "Rev. A" flash. I do not know what his experience has been since he has gotten the re-flash. You might check his posts, or send him a PM.
If you have not done so, you might read my thread "Understanding regeneration".
Good luck,
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