[03 lowered envoy]

mine was doing the same thing.if you have the auto temp control hvac system the dealer can reprogramme the hvac module to activate the after blow feature.if not they install an after blow module. It turns on the heater blower to dry the evaporator core so the mold can't grow. Here is the part # 12497910. to get rid of the smell open the glove box and lift the little tab on the top left to allow the glove box to swing all the way down.then put the heater in recirculate mode and run the fan on high. spray the cleaner in to the hvac box at the top through the glove box hole, I used lysol and it seemed to do the trick.once it starts coming out the vents turn it off and let it sit. then after a while open the windows and turn on the fan and air it out.This worked great for me.let me know how it turns out.
Chris.