Regen problems

What engine and year of truck

 

Probably an issue with after treatment hydrocarbon Doser. Or a differential pressure sensor on the dpf. Most likely cause is from not getting the dpf and catalyst not got enough to complete a regen. If the dpf doesn't get hot enough to complete a regen the pressure sensor will think the dpf is plugged and request a parked regen. If it is still doing a passive regen your soot level isn't high enough to only want parked regens but will eventually and then derate when or gets bad enough. Things also affecting regen quality are fuel pressure from after treatment doser air possibly leaking into system. The delta p sensor on the dpf and condition of the catalyst and dpf. Boost leaks and turbo function (vgt) could play into it. Usually not a big deal to figure out. Also might want to find last time when dpf was out and cleaned. Also excessive idle can load up a dpf with hydrocarbons and if bad enough will not be able to burn off. Regen temps for 07 emission trucks ranges from 840 degrees to about 1130. Anything over that will kick it out for over temp. There's a few other things that could affect but these are the usual suspects

 

I think all yer truck troubles are caused by all that fur on yer face....

 

It's only a 400 so you can't make it work as hard as a 500+, so the DPF may not be getting hot enough. What sort of driving are you doing? Local, short haul, freeway, flats, hills, ?? The harder they run the less regen time they will need, but if you're going easy on it then it may be getting sooted up.

 

Dozer is prob bit the dust or clogged. Only way to look at this is with insite plugged into it and check the temps.

 

Doser or sensor, if the temps don't get high enough it won't even try. I have also had an ISX that ran me in circles until I took it into the dealer for a forced regen. A parked regen should take about 30minutes, this one would run for about 12 and then go to normal idle. It had also had the DPF cleaned fairly recently, but still had issues. Once the dealer did the forced regen it was ok. That same truck did blow the EGR cooler in the midst of all these issues, and the coolant may have contaminated the DPF to the point it didn't want to light off properly.

 

I watched the complete video series on this. I'd say it's the doser. The doser sprays fuel just before the DPF. That is suppose to cook off the soot. The doser tip gets crusted over in time with soot, and no fuel comes out, so the ECM & EGR keeps requesting a regen, because your just barely burning off the a tiny layer in the DPF.
Go to rawze.com. This dude has a complete U Tube video series on this, and one for this exact problem, step by step. It's all for Cummins engines too.