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Discussion Starter · #1 · (Edited)
See image below. DPF loading fluctuates erratically with driving. Linked only to how much "power" is being generated. In other words, more throttle, more hill climbing, etc. It will also go up if going down hill, off the throttle, set in lower gear so as to engine brake. It just doesn't go up as much but it does go up. All of this results in premature triggering of active regens. Oh, yeah, it doesn't do it during the winter months (below ~45F). This all started summer 2020.

Any ideas? ECU hasn't set the light yet.

Edit: Added more plots including differential Pressure sensor.

Rectangle Slope Font Parallel Pattern Slope Rectangle Font Parallel Pattern Rectangle Slope Organism Font Plot Slope Rectangle Plot Line Font Slope Rectangle Font Parallel Pattern
 

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So i dont know if what u are looking at is actual dpf loading. What it looks like is average pre dpf pressure. This graph seems to follow the amount of airflow through the dpf - which directly relates to RPM.

U allude to triggering of premature active regens.. how many miles are u getting between regens?
 

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Discussion Starter · #3 ·
So i dont know if what u are looking at is actual dpf loading. What it looks like is average pre dpf pressure. This graph seems to follow the amount of airflow through the dpf - which directly relates to RPM.

U allude to triggering of premature active regens.. how many miles are u getting between regens?
The first graph is the DPF soot load. I've check the PID and before May 2020 it made sense. It would go up steadily. Bit faster when cold/warming up, slow and steady when on the highway, trigger a regen above 65%, go back down. Rinse and repeat. During the winter and daily driving it was about 125 miles between regens. During the summer it would be about 140-150 miles between regens with daily driving. On long highway trips I get over 400 miles between regens. Now it is about 75-80 miles unless ... get this ... I'm on a long highway trip and not towing. However, during the winter months of 2020/21 it was back to pre-May 2020 activities for absolutely no reason whatsoever other than outside temps below 45F. I suspect a quack sensor but no dealer mechanic will investigate outside their "'training".
 

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If you are on a stock tune, i never got more than 80-100 mi between regens. A lot of stuff could drive that.. fuel differences, temp, clogged air filter etc ..

Keep in mind as well, if you are stock, your intake can be sooted up. That will choke off airflow and cause more soot generation.
 

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Discussion Starter · #5 ·
If you are on a stock tune, i never got more than 80-100 mi between regens. A lot of stuff could drive that.. fuel differences, temp, clogged air filter etc ..

Keep in mind as well, if you are stock, your intake can be sooted up. That will choke off airflow and cause more soot generation.
Yes. I'm on stock tune.
 

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I don't see an issue here. Does the truck operate normally?
 

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Discussion Starter · #7 ·
I don't see an issue here. Does the truck operate normally?
Graph one does not make sense. Soot loading should go up at some rate. Faster when cold, slow and steady when warm, etc. Instead it can jump 10, 20, 30 and even 40 percent when climbing hills, accelerating out of a stop, and even when engine braking. It then slowly falls back once constant engine power has been achieve. Prior to May 2020 it did not do this erratic up and down. It is not going into passive regen as the exhaust temperatures are too low. Fuel mileage is fine.

As for performance. Other than being a laggy POS when tipping into the trottle from a dead stop and sounding like a 60s JD tractor when coming out of idle ... it's fine. Pulls our trailer fine. Gets 26-28 mpg on the highway on line trips (family and me) and 11-13 mpg pulling our travel trailer. Acceleration is good once it gets out of the lag POS action.

Edit: more plots:

Slope Organism Rectangle Font Plot Rectangle Slope Font Pattern Parallel Rectangle Slope Font Parallel Pattern
 

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Discussion Starter · #9 ·
Well. I'm down to about 45 miles average distance between regens. Depoends on the mood it is in. Long trips with no trailer I can get hundereds of miles between regens. Pulling the trailer can be 25 or 50 miles. Just hoping it will blow the hell up soon.
 
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