This dag on Cummins isx 15 code1921 dpf full

[Rawze]

Check the little tube and circuit for the exhaust pressure sensor on top of the thermostat. Make sure all sensors are also OEM only. Also check the sensors under the truck at the DPF, DOC, etc.

DOC missing is not a normal code to get when the system acts up.

Might also need to remove the DPF filter and see if it is actually clogging up like the alarm shows.

The engine is only going to last so long before it wears out to the point that it cannot keep those cans happy at some point.

Any regular coolant loss?... oil consumption?. etc?.