Temperature, in the long run...

I agree that placing the snake with someone willing and able to pay for vet care is the BEST scenario.

IF you aren't willing to go to the vet or give up the snake, please look up info on respiratory infection and make changes to your husbandry accordingly. Some mild RIs can be treated with increased temperature and proper humidity. If that's as good as your snake is going to get, it's better than nothing!

It's possible that the "sneezing" is not an RI but a vet checkup is the only way to know for sure.

Well, I'm not sure about this, but he was coming from being kept in a humide tub, to my 30% humide viv...I upped the humidity by closing off some of the screen top and I haven't heard very much of anything coming from him...

Dustin