I am getting exhaust inside the cab when I turn on the vents,air, or heat.
Does anyone know where to start looking?

2005 F-250SD 6.0

Thank you in advance

 

I you smell it when your AC is bringing in outside air then you probably have an exhaust leak under the hood somewhere. possibly where the up pipes connect.
im sure someone else will know more

 

I feel you pain. My 03' went in 3 different times for exhaust. Make sure you have a GOOD dealer. I went to one dealer that told me it wasn't leaking. I took it to another with a better reputation and they found my Y pipe was cracked and said it was very common. It craked again 18 months later and I also had a turbo pipe crack that put it in the cab.

Good luck.

Nate