Is it due to shed soon?  If you don't see mucus or other signs of an RI (black throat is normal) then just watch it closely for now.

+ 1 bart If he  is going into shed he  may  just have clogged nasal passsages  I would bump up the heat a little  and keep an eye on him 

Every now and again my retics will do this, it seems they're trying their best at sneezing.  Usually it's when they're getting ready to shed and there's some dry skin in their nostrils.  If no other RI are present, I wouldn't worry.  But I'm not expert at Chondro keeping.

I agree to keep an eye on him, if he continues to do this after the shed it might be time for a visit to the vet, just to be on the safe side.

squeaks in chondros typically are a-okay. i've been thrown by  a chondro going into shed more times than i'd care to recount.  I don't see any sheds in Shreks tracking yet, so he could be due.

next time you have him out, feel where his lungs are, when you have an RI going you can actually feel the rattle. there's a huge difference between the shed sounds and the RI sounds, and you'll be able to pick them up from across the room in time. posture and behavior are also tell-tale signs once you get to know them. You can just look at the snake and be like, oh, that's wrong.

in my experience, my math says everything is going to be fine, you have a shed coming on.

Thanks everyone, his behavior has not changed at all he is still very active and he is feeding great as well. I was just being a concerned chondro owner, but i will make sure to keep a close eye on him

please follow up with this in a couple of weeks or after shed if you don't mind... would love solid closure on this :)