Hole in DPF housing causing problems?

This is my 1st post here so I hope I am doing this right. I got the "scr performance low, repair needed 5mph limit at next vehicle stop". Codes we're 4094 fmi 18 and 5246 fmi 16. Took it into the shop and they drove it while connected to computer and said it was throwing out waaaay high nox value 300 ppm at idle 750+ when climbing with empty trailer. They found my egr valve to be bad. I paid and drove it 17 miles and same codes came on. After 2 days of diagnostics they came to the conclusion I needed injectors, cups, dpf cleaned and doc serviced. Paid and drove 300 miles same #### lights and codes now they are saying I have a hole in the bottom of my dpf filter housing and that is the reason it is throwing high nox and not doing a regen. 2013 Mack cxu613 mp7 engine. Does this sound like the problem to anybody? I am currently 11k in and don't want to spend another 5k if this sounds like bs

 

This is my 1st post here so I hope I am doing this right. I got the "scr performance low, repair needed 5mph limit at next vehicle stop". Codes we're 4094 fmi 18 and 5246 fmi 16. Took it into the shop and they drove it while connected to computer and said it was throwing out waaaay high nox value 300 ppm at idle and 750+ when pulling empty. They found my egr valve to be bad. I paid and drove it 17 miles and same codes came on. After 2 days of diagnostics they came to the conclusion I needed injectors, cups, dpf cleaned and doc serviced. Paid and drove 300 miles same #### lights and codes now they are saying I have a hole in the bottom of my dpf filter housing and that is the reason it is throwing high nox and not doing a regen therefore throwing the scr code. 2013 Mack cxu613 mp7 engine. Does this sound like the problem to anybody? I am currently 11k in and don't want to spend another 5k if this sounds like bs

 

The only reason I could see that they did not catch it is because I do see some insulation through the hole so maybe they only looked at it when it was opened from the top to send my filter to get cleaned and the only way u can see this hole is from the bottom. Not trying to make excuses for them as it is just poor workmanship either way.

 

Nox sensors were changed in march. They pobably ran around 50 tests testing everything emissions related. I originally got a code and check engine light in March for the nox sensors which is why I changed them. This time I got the lightning bolt and the message but no check engine light

 

I texted the original tech about what the new shop found and asked what he thought and this was his techs response