i have a 2001 Pontiac Montana and when i first start the van and turn the air on it smells bad through the vents for a little bit at first. anyone know what i can do about this to get rid of it? the smell is kinda staying with the van even without the air being on.

Open the glove compartment. You will find a cover in the back. Remove the cover and open the door. You will find two cabin air filters. These can be purchased at AutoZone for about $30.

I can't find the filters at any auto store near me but I have taken out the originals and cleaned them (shake and remove debris) several times. Bad smell can also come from the AC evaporator. GM sells some spray that requires you to drill a hole into the plenum and spray in the disinfectent. You could also probably use something like lysol or other spray disenfectent.