Depends on how close they look. It’s possible to hollow out the dpf and scr then run tuning that shows obd2 readiness moniters as good. Then the truck well sound good with a filter back exhaust.
When your truck has a cel thats causes limp mode aka service electric throttle message. It well lock out regen from happening. The cel which is likely unrelated probably caused your dpf to fillup. Its best to get a obdII scanner and read then clear your codes before they cause bigger issues.
Most likely it’s a loose connector on your truck don’t make a big deal over a small problem. The trailer brakes are a completely different circuit thus meaning it’s a wiring or electrical issue, not a system issue.
What you need is to either change your/her driving habits aka more highway miles. Or trade the truck off an a gasser which is the easiest option. Unfortunately doing more and more forced regens is not a good option in the long run you well end-up having issues eventually with the dpf clogging.
The ecoguard is actually an excellent filter. Ive compared it with a factory mopar filter and they are identical except the o-ring. Oil analysis proves they filter excellent. Basically im yet to find anything that proves there not an excellent filter.
Unfortunately without more info you won’t get much advice. Things like the actual code that says why its faulting are essential for fully understanding the situation. It is likely something uncommon or hard to diagnose at this point but without a starting point we have little to guess off of.