DD15 low NOx conversion efficiency and bad DEF Quality

Run another regen, monitor the SCR inlet and outle temperature. If they are more than 25ﾟ apart during the last 10 minutes of the regen it is an indication of A internal a failure of the SCR. Also monitor the doc and let pressure if it is above 1.16 it is considered face plugged.

 

not always correct. wrong in 50% cases. 25 difference of nox reading could indicate drifted sensor. 1.16 + psi pressure could indicate need of new dpf s

 

Everyone thanks scr Knox conversions low. Must mean bad dpf filters. Wrong. Scr converts in the bottom of the one box. Replacement dpf filters does not lift Knox conversions. This can only be accomplished by replacement of the one box it’s self. The scr is not serviceable.

 

or you can let outlet Nox sensor sniff clean air if you are not a tree huger ))) you will nave 100% conversion without check engine light.

 

Singh saab,
I am having a similar issue with a 2016 cascadia but my question is regarding the warranty coverage. Did u buy extended coverage as mine is covered till 500k but the freightliner warranty coverage page says SCR (1 BOX) is covered for 24months and unlimited miles. Mine is still under 500k.

 

How do you do that?

 

search dd15 scr bypassing on Youtube.

 

####, and I just replaced a nox sensor. I could have done this. At least I gained this knowledge before spending 10k

 

Hi, I'm having the same problem. When I regen the truck, efficiency is at about 90%. After it finishes i saw that it dropped but also saw that the injection rate dropped from 10-11% to about 4-6%. It rose again for a bit as did the efficiency but began to drop again. The efficiency was at 50ish% when the graph finishes. Is this a ACM problem?