Any Help With Fault Code 3582 Spn4364.18

For that fault, the 1st thing I do is test the DEF with a refractometer. I have found very few issues with contaminated DEF, but it's so easy to check, it only makes sense to eliminate it first. Then look for external DEF leaks and exhaust leaks, which it sounds like you've done that.

The most common issue I've found causing that fault is a plugged DEF doser. Now you want to use Insite to perform the "Aftertreatment SCR System Test". If it fails, you can do a DEF doser override check, which involves removing the doser from the decomposition tube and measuring the flow. If that fails, there's a good chance that it needs a new doser.

 

Sorry, I missed the new doser part, I though you just cleaned it. Did you run the Aftertreatment SCR System Test? That will help narrow it down some. If that fails, then you should then do the doser override check. The override test will tell you if it has the correct flow, which will eliminate the pump/delivery side of things. If the flow is correct, then you'd be looking at an outlet NOx sensor or a catalyst issue. It's rare, but I have seen outlet NOx sensors fail without setting faults.