[///Mposter]

Originally Posted by jxterma

I changed my cabin air filter last week. It's a fairly quick job with the instructions above. Now the AC starts making "popping" noise when switching on/off AC Max. It sounds like some flap is striking open/close.
I checked the air intake duct with flashlight when my buddy was toggling AC MAX. It seems the noise is from a yellow plastic flap flipping up/down.
Do you experience the same? Is there any quick fix?

I think the flap you are talking about is the one you should be able to see when there is no air filter in there. The Max AC will pull inside air only, so obviously it would close off outside air.
Do you suppose the bottom filter isn't seated correctly and it falls back down after it closes? Or do you think it is just the flap itself may have lost its foam lining to quiet the mating ?
Personally I haven't run into that specific issue.