cummins ISX SCR/DEF service rrquired

I am currently in the shop now for scr codes i will update the exact faults codes and cost of fix ASAP

 

After getting engine air filter replaced at TA Shop next day my SCR warning came on,, possible that mechanic didn't remove a piece of plastic from the filter and it's clouging the air flow?? Makes me wonder. My DEF fluid filter was changed 70k miles ago and they're recommended to be changed every 100k miles.

 

I read that if engine air filter is clogged oxy sensors may pick up different oxygen levels in the exhaust which may trigger the scr code. Small possibility because scr is basically the DEF fluid injection system, def pump, def fluid filter, def fluid inline heater, def fluid injector. People seen that happen. Maybe their control modules were little cooked up.

 

If your air filter was plugged or severely restricted, you'd be complaining about how gutless the truck is long before it started throwing codes.

 

Where in MD?

 

Dash code. Pestering Spn:4364 fmi:18. Had Kenworth las vegas run diag. Including manifold leak test and turbo, vgt analysis. Turbo back pressure which wasnt creating anything out of spec. But unnecessary spooling was caused by failed SCR according to tech. Diag. No manifold leak. Earlier during a parked regen I did notice smoke coming from the flat end side of the scr which would indicate a crack and that would probably indicate not enough heat from the exhaust gas and why I'm getting code with amber light and having multiple regen attempts. Keep in mind that it has a new fuel doser/ def doser, I took the def tank off changed internal filter, new def pump, new def line, new def harness from pump, took DPF/doc off and had it cleaned/inspected, new dpf/doc temp sensors, imap sensor, atmosphere sensor, new EGR within the past 8000 miles, cleaned out 7th injector fuel line, new nox sensors. Had Kenworth clear the codes and drove home to Denver, half way home, code reappeared, no derate and now have it all torn apart and waiting for new scr. Will update when new scr is installed and parameters are reset and any ecm updates installed. Will reset regen campaign.

 

I have a Cummins and got 4794-31 code took it to Cummins and they told me everything is reading fine but the check engine light is still on