Bad DEF quality and Nox sensor ? Check engine lights but they come and go

why you need it? plugged doc face will not cause low nox conversion. i would check to see def injector awning is ok.

 

Yes, exactly. I saw a video of the DEF awning install. He said if you do have a lot of def build up, that a series of regens can clear up the old stuff.
So I ran the face plug routine today and watched my NOx efficiency hover around 81%, which is too low. 70 minutes into the routine the efficiency climbed up to 88-92%. Satisfied with this, after two hours I aborted the routine. Let the engine run at 900 rpm until temperatures cane back down. Then did a standard parked Regen. NOx efficiency still was low 90%.
My thinking is that this would clean up the deposited def build up. Tomorrow when the truck is back working, I’ll watch my outlet NOx sensor, if the numbers are back to normal, then I’ll know that I need the awning kit. Seeing as I’m due for DPF filters soon, that will be a good time to do it.
The face plug would show high DOC inlet pressure, but mine was under 0.5 psi. So it was good.

 

Started the day with 2 codes , nox conv eff and Def Quality. Previous day ran a tank of Lucas diesel deep clean Dpf . Well 2 times truck was asking for parked regen and I just kept driving lights went away and 1 of the 2 codes disappeared. Plan on pulling metering unit give it a clean out and yanking inlet and outlet sensors , I will try cleaning and replace if that doesn't work . You can buy both sensor's on Ebay for half of what Freightliner is asking. Oh well the Dpf gremlins didn't win this round !

 

Looking good so far.
Last week I was getting 4364/18 everyday.
Outlet NOx sensor was reading 190-240 ppm under full power, sometimes would go over 300 ppm and set code.
After doing the extended Regen (doc face plug routinef two hours) this weekend: today I'm only reading 60-80 ppm under full power. No codes at all.
So looks like I'll be getting a DEF Awning kit for my one-box.

 

if your engine is epa10 you need to check also def pump bladder air pressure.

 

GHG14 2016 DD16 600/1850

 

All codes gone no lights lol I really hate this system .

 

Any updates? Thru some more codes and derated, limped to a shop . Forced regen and reset , I need to get home so I can work on this thing.

 

Been almost two weeks since I did the extended Regen. Still no codes.
In my case it's looking like I need a DEF Awning Kit

 

Replaced nox sensor 1200 after 1200 new metering withva few 400 in between to see if regen worked. Didn't had to limp a lot. Derated now trying new dpf filter 400. Under load. Not fun. Want dpf problem done. Bought obd2 scanner with regen hope it works to regen ever now and again as it does not do it on its own. Not sure where going hope not replace or something near. Come on truck designers and engineers get this dpf system fixed for future trucks. Lol