Cat 320 NOx conversion

[pumkinhead]

working on a 320 (HEX) that intermittently throws a E1410-2 - Aftertreatment #1 SCR Catalyst Conversion Efficiency : Erratic, Intermittent, or Incorrect. every few days or so. the def injector failed and was replaced a few months ago and i have verified spray pattern, dosing accuracy and the mixing chamber looks clean. there are updated NOx sensors and software available but would like to verify what the issue is before throwing parts at it, any suggestions

 

[Island_catguy]

When it failed, was there any build up on the tip? You are sure it’s clean in the mixing chamber?

So that particular code is one of the hardest to clear. CAT tells you to run the aftertreatment recovery procedure multiple times to try and burn off everything.

I personally just pull the scr apart and clean it, then run the tests.

Also, with cat ET make sure you pull a product status report. It will show other codes that might not be popping up.

Under diag tests, there is a systems communication test. It shows if one of the components on the data link fall off. It is very helpful when diagnosing emission sensor faults. You can see if the nox or nh3 sensors are losing communication sometimes.

And always drain and refill the def fluid. If you have a nice cone shaped spray, and you camera the injector hole and it’s clean, run the after treatment recovery procedure a few times.

 

[pumkinhead]

thank you, when the injector failed i didn't pay much attention to it, there was some crystallization on the tip and the mixing chamber looked good and i verified it was clean about a month after with a borescope when the nox conversion code first popped up and did and def accuracy test and verified spray. i did drain and refill the def tank, i have ran the aftertreatment recovery twice but not back to back

 

[Island_catguy]

and you have run the aftertreatment functionality test?

All you need to use when cleaning is water. The crystallized def fluid becomes soft when water soaks on it. I usually use a leaf blower after to blow as much water out, then put it back on and run the machine at idle for 30 mins and it should dry everything out.

 

[pumkinhead]

have ran multiple function test but by the time i get to the machine the codes not active, warm distilled water works great

 

[Island_catguy]

As

have ran multiple function test but by the time i get to the machine the codes not active, warm distilled water works great

yeah in your case then I’d pull it and clean. Still take a PSR just so we can check what is happening when the problem is active.

 

[pumkinhead]

update - installed the updated NOx sensors and updated software and so far so good
("New engine software is available. The new engine software has been updated with improvements to the thermal management strategy within the aftertreatment. E1309 (2) NOx Conversion Is Low can become active due to deposit formation within the aftertreatment, due to low exhaust gas temperature during low-load operations. The increased thermal management within the aftertreatment will raise the exhaust gas temperature during low-load operation to mitigate deposit formation.")

 

[Zewnten]

Yeah the software update tweak parameters and then everything magically works. Been there will irritated customers breathing down my neck and cursing CAT