Deleting the dpf and supporting systems is a federal crime and in some states.
The epa will impound or heavily fine you and the company for the volition and if your found to not fix the delete you can wind up in jail.
I would look at if the filter can either be cleaned or changed first.....the injector does fail but they should have tested it and told you if it was bad.
Do not under any circumstances break the inside of that filter out trying to clean it because if your found to have broken out the filter it is a hugh fine from the dot.
Look past the hose. Question is that a exhaust line powering a turbo? The blockage is past the hose somewhere your best bet is to see which direction the air flow is and work backwards from the hose.
Sounds like something is blocking the hose.
Do you have any maintenance records for the truck and does it say if anything has been done to that system?
Make and model of truck for our repair gurus.
And fyi most turbos can be rebuilt.
Alternator, starter, anything that the belt runs can make that noise. So failing bearing can make it.