Regen too often

A forced regen almost always pulls the soot level down to acceptable limits. The better way is looking at the history, times and temps of all the auto preformed regens.
Oil consumption, faulty injectors, DOC not getting hot enough, burning coolant and faulty wiring to the dpf differential pressure sensor can all cause incomplete/ too frequent of regens. DPF even been cleaned or replaced? Engine been updated to the APR liners/pistons? Can you post the regen history?

 

Man there are a gazillion reasons. Especially with truck being 7 years old. Filter was cleaned last year, but needs to be done every year. The doc needs to be cleaned, the venturi could be clogged, the sensor that sits behind or inside venturi tube, could be dirty. When it is, it doesnt see clearly. So it thinks filter is full and asks for regen or parked regen when it really not needed.

 

Most often, your truck will keep regaining often because it never did a proper one to begin with.

Google Cummins isx egr tuneup, Rawze has a good video series from a older isx but it will give you a idea of the different components and what your fighting.

Just going through and cleaning everything and replacing a couple hundred dollars worth of sensors will make a night and day difference to your truck.

That all being said, there could be other reasons as stated earlier.

I would start with a emissions tuneup before anything else, I've personally seen 2 friends buy new turbos when it was just a bad imap sensor.

 

It will be a tube or pipe that is between your EGR cooler and fresh air intake. It has 2 holes that go to a pressure sensor that can get clogged up with soot. I think it signals your EGR valve to open or close based on what the sensor at the end of the holes is reading. One of the symptoms I noticed on my Volvo was that the turbo boost had a slow response and it wouldn't hold steady, constantly bouncing +/- 5 PSI. I don't think this will fix the problem of regen too frequent, but you might as well clean it out anyway. I actually recommend going through the whole system and cleaning it using the videos and resources from Rawze. Even if it's not the same engine, they all work pretty similar.

Fixing your EGR/DPF Problems...

There are also the 2 rigid lines that connect the DPF canister to the Delta P sensor. The one that is before the filter can get dirty with soot, so I would clean that tube out. The post filter tube shouldn't be clogged up, but it shouldn't hurt to shoot some carb cleaner through it. Make sure that there are no leaks in the lines or hoses when it's put back together.

I have the OTR performance tool to reset the codes and soot gauge also. It's come in pretty handy for helping me to finish loads and work on the problems on my own time without getting derated.

 

I drive a 14 Pete with the ISX 15, I have the same issues, it tries to Regen every day, and usually every day it seems to want to run a Regen again, only doesn't idle up and doesn't turn on the hot exhaust light. Just seems to put a dummy load on the turbo. Cummins cleaned my filter last year, it ran perfect for 5 weeks, now back to the same twice a day. One false and one real regen. No CEL, so Peterbilt and Cummins just keep scratching their heads and make no headway.