P20EE Let the Fun begin.....

[tom318]

Truck has had some strange things going on over the last few weeks and unfortunately it was in and out of the body shop with issues so I haven't been able to diagnose or take it to the dealer. Since then I also rolled over 80k so the emissions warranty might not help. I noticed over the last few weeks reduced fuel economy, increased DEF usage and white residue in the exhaust but no CEL. I was working with the body shop at the time but they couldn't find anything wrong and had me return a few times. During that time I took 2 trips which put me at 82k miles and now the P20EE light came on.
I notice the truck is a bit down on power, still struggling to see over 23mpg and DEF is being consumed quickly. Truck is going in tomorrow for the DEF recall which hopefully will help but if not I was going to look into cleaning the DEF injector. Other than that, i may need to relay on the dealer or an independent shop to help with the fix.
Any else deal with this code on the 3rd gen motor?

 

[tom318]

DEF injector looked clean. DPF look filled with white(DEF).
One of my scan tool had live data feature the nox sensors and it looks like the downstream sensor might be bad? Anyone know what these should be reading? NOx was just sitting at 65535 and didn’t budge.

 

[tom318]

Dealer suspects failing scr and that’s the residue I’m seeing in the muffler tips. I put a camera in through the down stream nox sensor and the quality is rather low but it does look like it might be clogging up. Hard to tell. Anyone ever drop the SCR and clean it or have a baked?

 

[2021EcoDiesel]

So not with my truck, but with a 55 horse tier 4 Yanmar diesel I had a CEL and an on board computer constantly asking for “Recovery Regens.” The machine would disable its PTO and need to be parked for 30-45 minutes ~4 times per month. Pulled the DPF and had it baked and that solved the issue. Now mind you this is on a tractor with 4000 hours, not a truck. Working speed is 2700 RPM and this thing gets ran like a red headed step child. My Ecodiesel has 55,000 miles and only 1600 hours on the engine. But, I imagine at some point I’ll pull it’s DPF and SCR for a session in the oven.

 

[tom318]

I'm currently at a loss. I cleaned the NOx sensor and the CEL went away. I had the DEF recall done yesterday as well. I'm not convinced the Truck is ok, especially based on the mechanics responses to the residue in the exhaust. They want the SCR and DEF injector replaced and said it "should" be covered under powertrain warranty but they weren't sure themselves and asked me to reach to out Chrysler or RAMcares to see if they could support the issue. Mechanic said they haven't seen that before but mentioned it looks like it could lead to some trouble. He mentioned it may have been due to the DEF issue the recall should fix but possible to late for me. Without spending lots of diagnostics money there's no solid answer at the moment. I am looking into a place the could bake the SCR but no great leads yet.

 

[2021EcoDiesel]

Also, based on the code and that sensor data being static I’d wonder if maybe that sensor is bad. I’m not a fan of just throwing parts at problems, but maybe check the wiring around the sensor and/or replace the sensor. Cause P022E relates to catalyst inefficiency, which would be measured by those NOX sensors. Perhaps it thinks it’s running inefficiently and If it’s measuring too much NOX gas maybe it’s overcompensating by dumping too much DEF into the exhaust. I imagine a failing SCR/DPF would cause the same issue.

 

[tom318]

Also, based on the code and that sensor data being static I’d wonder if maybe that sensor is bad. I’m not a fan of just throwing parts at problems, but maybe check the wiring around the sensor and/or replace the sensor. Cause P022E relates to catalyst inefficiency, which would be measured by those NOX sensors. Perhaps it thinks it’s running inefficiently and If it’s measuring too much NOX gas maybe it’s overcompensating by dumping too much DEF into the exhaust. I imagine a failing SCR/DPF would cause the same issue.

After cleaning the downstream Nox sensor it does seem to function. I just don't know what a good reading is but its not throwing any codes so I can only assume its good? It reads 1-5% of the upstream Nox but when i stand on the throttle it reads much higher and will stay high for several seconds even when nox 1 reads 0. Just speculating but it seems like the exhaust gas is struggling to get through the SCR, id expect the 2 sensors to read closer to each other.

 

[Rossum]

After cleaning the downstream Nox sensor it does seem to function. I just don't know what a good reading is

If you can get PPM from your tool, it should be lower than the upstream; ideally by a factor of about 10:1, with it all warmed up, of course.

Disclaimer: This is not something I've checked on my truck, but is commonly accepted for Euro diesels with SCR systems.

 

[tom318]

If you can get PPM from your tool, it should be lower than the upstream; ideally by a factor of about 10:1, with it all warmed up, of course.

Disclaimer: This is not something I've checked on my truck, but is commonly accepted for Euro diesels with SCR systems.

That is what Im now seeing. After the y81 recall + the truck went through a regen and during that regen I drove it harder that usual in an effort to bake any off. I know the regen has nothing to do with the SCR but I figured the additional heat from that process could potentially help bake/burn anything out of the SCR under high load/high flow rates. Since that, the white residue is gone, fuel economy went up and all seems normal.
During that initial trip I must have had an issue with the DEF injector or a sensor, though it never threw a CEL.