(01-04-2020 )JimT Wrote:  So I just cleared up my own dpf issues. found a bad egr valve. for me it was causing exhaust temps to be too low resulting in occasional grey/blue smoke only while it tried to active regen. it also would cause the regen to end prematurely, which resulted in the "too frequent regen" code.

One other thing to check if you are smelling fuel during regen is the exhaust bellows connecting the back of the doser to the rest of the exhaust. they flex and wear out and when mine went this past summer it resulted in the same fuel smell you mentioned.

from that last picture you posted it looks like your getting a lot of incomplete regens. This was one of my problems prior to replacing the egr valve and doing the egr tune up. If the valve is still good and sensors are new then check to see if there's any wiring problems. broken, dirty or corroded wires and connections could lead to bad sensor readings that halt the regen in progress.

for me, finally replacing the EGR valve (after an EGR tune-up and new bellows) is what got things regenning properly. and no, I never had any egr related codes to tip me off either.

side notes:

EGR valve.
When I inspected the EGR valve i first noticed excessive soot coming out of the weep hole on the back side. Quickserv says some soot is normal, but this looked excessive. next when looking inside both sides had a fine, dry and thin layer of soot build-up and the valve appeared to be closed. disregarding the instructions in quickserv/insite I LIGHTLY pushed the valve open. it had almost no resistance and did not close at all. It also left a trail in the soot build-up that hadn't been there before.

Doser.
6 months ago I removed and cleaned the dpf doser. build-up wasn't bad but I noticed the thermal isolator was thin and compressed in to a hard disc. cleaned off the doser but didn't replace the thermal isolator at the time (didn't have one on hand). fast forward to now, pulled the doser 6 months later and it was caked up with soot pretty good. this time I replaced the isolator and the new one was twice as thick and less dense than the old one was. I suspect that it's condition contributed to the rapid build-up in only 6 months. lesson learned: regularly check the doser for build-up, regardless of how new it might be. (my doser had been replaced 18 months ago when i bought the truck)

(01-07-2020 )JimT Wrote:  Just a few more thoughts based on your posts.

You mentioned smelling diesel fuel when regening. likely cause is exhaust leak between doser and dpf, which you might have fixed already.

The soot build-up on your DPF is uneven. It's possible you have liquid getting in a causing higher build-up in those spots or maybe some of the passages in the DPF are getting clogged up. When was the last time you sent it out to be cleaned and flow tested? If I removed the DPF in your situation that would have been one of my courses of action. Helps to eliminate a possible issue.

Question, have you rebuilt the fuel pump? Are you getting good fuel pressure? One of the pictures you posted of the data monitor showed a maximum measured pressure of 9172 psi. I could be wrong, but that seems low compared to the other data displayed in that picture (attached to post 2). Also, low fuel pressure could contribute to the injector performance test failure. I am by no means an expert here, just commenting on what I see in the pictures. Maybe someone else knows where the fuel pressure should be during a parked regen?

Also, check the doser for soot build-up. If the fuel pressure is too low or there's too much soot built up it might not spray properly.

Two things not mentioned are the DOC and the SCR. Have you checked these for exhaust restrictions? DOC face plugging? Build-up in the SCR decomp tube? Ash in the SCR can? These could all cause higher exhaust pressures tricking the computer in to thinking that the DPF is full.

Finally, when I monitor engine data I usually check both commanded and measured values for things like EGR valve, fuel pressure, turbo actuator. Maybe you simplified it for the picture, but it's good info to compare.

Again, I'm far from an expert here, but I've done a good share of trouble shooting along these same lines recently. Hope this helps.

(01-07-2020 )Lonestar10 Wrote:  you could always put up whereabouts you are at and a member here might be nearby or coming through and could help do a tracheotomy on your truck if you carried all the parts to plug up the bad juju points in the system. if you have all the parts and ability to pull the trash cans out ied say...2 maybe 3 hours in a parking lot and your truck would have a clear throat and you could drive down the road popen a wuwu listening to the turbo sing.