Just looking for some advice on what you guys think

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I have had my common boa for roughly 1.5 years now and since day one I have heard a bit of a wheezing sound come from him (he is roughly 5ft - don't know his age but shedding perfect sheds roughly once a month). I don't hear it with every breath but more when he deeply exhales when climbing etc. It starts with a bit of a popping sound (not continuous - just one 'pop') but there is definitely no mucus visible or anything crusty around his nostrils. He appears to be healthy and eats well. I have his cage maintained at an average of 90F and drops to low 80's at night. I don't believe there are any husbandry issues for temp, humidity, hides, sanitary etc. and the enclosure is not drafty.
My question is, do you think if it were a respiratory infection that he has had for the last 1.5 years that it would have gotten worse by now? Is there some kind of treatment I can try just in case it is an RI? Any input / advice is appreciated. My fear is that if I do wait to see the gaping mouth / more positive symptoms to indicate an RI, it may be to late. Thanks in advance guys.