Bad DEF quality or ?

I have the same problem going on for 7 months, change one box, def metering unit, new def filter , def header, nox inlet and outlet sensor, every single sensor that has something to do with the def and I still have the same problem def qualitycode ... please help if you have any info? All repairs done in premier truck group Freightliner dealership ..

 

Have they checked the pressure limited unit (PLU)? This is mounted behind the transmission on top of the frame. It has a air line going to the inlet and air line going from the outlet to the meter unit. At times this PLU leaks air externally from the housing and if can be tested using Diagnostic Link or gets plugged/kinked, or simply doesn't put enough air pressure into the meter unit and you will get a DEF quality fault code. Did the dealer by any chance check to see if the aftertreatment control module (ACM) has the latest software? If your 1-BOX has been replaced another common missed error is checking the DEF dosing nozzle mounted on the 1-BOX... the tip can get crystallized or have a minor internal blockage from DEF (not the most common issue though)

 

Got international have a bout 3/4 tank of def but the truck say I have none it has derate all the way to stop engine but I have def in my truck what could be the issue how bad will it hurt my truck if I kept running it bc it getting def

 

International is a different animal. Maybe your DEF tank level sensor needs to be replaced.