Hi guys. Some updated information about all of the above. It is 2 and a half months since I was in that trouble. The guy who bought it from me I am friends with. He has spent approximately $10,000 getting that piece of !@#$ running again. No it was not the EGR sensor. The one box was removed and hosed out, yes I said cleaned with pressurized water. I saw a video on YouTube with a guy doing that. They cleaned all the muck of of it. So the dealership of Summit Trucks in Springfield lied to me.
The work was done locally not at a FL dealership. Various clamps and parts that got broken in the process had to be replaced and that was expensive. It needed 8 new batteries which was no surprise. There was nothing wrong with the APU.
I would NEVER advise anybody to buy a Freightliner Cascadia. They are way to up their own rear end to be a practical truck.
It was discovered that the house batteries are in some weird way tied in with the cranking set. If they are no good it disturbs 'the force'. That is ridiculous. Yet it is true.
This truck is so over engineered that it is a liability. Even if you bought one new, reassuring yourself that because it has 5 years warranty that all will be well, you would be mistaken.
I am glad I sold it. I am not glad I lost $35,000 in less than a year. However I am happy to be out of the industry. I could have, and still could, easily get a job as a company driver for good money but it isn't worth it.
Trucking is an enormous risk for little return. Full of people who want to shove others around, bureaucrats who make their bones thinking up new 'rules' (despite whatever Trump said), dangerous weather conditions and ungrateful people who should have NIMBY tattooed across their foreheads. The industry has always been a cesspool and nothing seems to be changing.
I shall be returning to electronics for my remaining years.
Best wishes to all on Truckers Report.