Sleeper fills with raw diesel fumes 2017 Cascadia after 8-9 hrs @ 60mph

My husband is driving a 2017 Cascadia (2 different trucks) high mileage (over 400,000 miles). After about 8 to 9 hours of driving @ 60mphs the smell of unburned diesel starts filling the sleeping berth and then cab. He's getting lightheaded, hard to breath, nauseous and generally miserable. He's complained and shopped the truck multiple times, but it's never resolved, his company have him a different truck, but has the same issues. It doesn't do this all the time, maybe once to twice a week. It doesn't matter if the fuel tank is full, empty or somewhere in between. He now drives, even in the extreme cold, with the windows open to try to ease the fumes. Any thoughts on what might be the problem? Has freightliner issued a recall, that's been ignored? He's been driving for 10 years and never had this type of problem before. Thanks.

 

Yeah, he thinks so too.

 

Thank you everyone. He's going to tell the shop about the flex hose, he does think someone is messing with him to get get him gone. And he's tried everything to blow the fumes out of truck, but they just linger on. He's reported these trucks and they just act like he's crazy and a complainer. He eats a lot of #### doing this job, and this has just gone too far. Thanks again, and if anyone else has any technical input, we'd love to hear it.

 

He runs out of Sparks, NV. He does NOT want to go into Calif. Right now he's doing Sparks to Portland twice weekly as a dedicated driver. PU at 11 pm and run overnight. We would really like a day job heading anywhere but west.and running four days a week, I know, high hopes, but it's gotta be out there somewhere.
Thanks