DD13 code Spn 6259 fmi 0, anyone have experience with this?

Does any one have experiance with this code. ? It a cascadia dd13.
I don't want to miss anything. I was able to down load something that explains how to start at the p sensor. And test all the way down to the egr butterflies.

So. I was derated 25%. With spn 411 fmi 13. It brought me to the p sensor. I took a day and learnt how to clean and Or replace whichever was nessacy. A simple five min cleaning and I was back on the road.( test driving the nox sensor replacement) about ten mins in I was derated again same code.
I pull over and clean again. The first cleaning the engine was cold. The second cleaning I was at highway speed. I noticed when I removed the sensor. The front port was wet but the back port was not. So I cleaned it again. Looked at the dash and the new spn code is 2659. Fmi 0
According to what I just read. It is either the sensor that moves the butterfly in the egr or the actual butterfly is jammed. Causeing a uneven return flow causing the soot to clog the p sensor.
Any advice from some one who has done it woukd be great. Or any questions if I complacated my question.

 

Thank you.
It always comes in groups. When its good its great and when its not its not. Half of the problems could be prevented by cleaning it seems. But not knowing what to clean and how is giving me a crash course.
But once I know I can't blame any one but me. But thanks again

 

Wt5for. qt55ըտԸգ*

583,417 miles

 

Yes on the cool ant leak.

 

Will so this weekend