[CaptainGizmo]

Steve,
This is Bob Repka. I spoke to you several times last August when I was looking at a 2007 Newell for sale in San Diego. Thanks again for all the info you gave me in that process.

Hopefully you found the problem by now, but if you didn't, consider the following. Its possible that fresh air may be entering the exhaust system between the DPF and SCR syatems. If this is the case, the DEF that is atomized into the system may condense at or just after that point due to slightly lowered gas temperature. If that is the case it will pool and leak leading to crystalization. If any of the remaining DEF is liquid rather than mixed in the exhaust gas, it can pass through the SCR and spray out of the exhaust pipe, as you cited. As an example, check out this link: https://www.bigmacktrucks.com/topic/3879...bowflange/
Did you happen measure the emissions? If you have a base reading you may see a difference as well before correcting this.
Your picture showed a crack in the exhaust pipe near the crystals. Is this area between the DPF and SCR?

Hi Bob!

Yes, I sure do remember you, and thanks for your appreciation!

And, thank you very much for your help with this DEF deal. You've got some good thoughts goin, and all of this may help with the solution.

I have another lead for a guy who "supposedly" has had experience with this, along with a solution. We'll see.

As to your speculation, the "crack" you refer to in my photo is not really a crack, but a clamped joint that's between the crosspipe and the SCR. So, the DEF is sprayed into that crosspipe, then needs to travel pass that joint and into the SCR.

I've had that clamp and gasket replaced, along with the DOSER. So, seems like it would be one of three things:

1. The new doser is still not atomizing the DEF enough
2. The ECM is still overdosing the DEF
3. The clamp/joint is still leaking

To be continued...