THEhomelessONE

Every other car I've owned, the smoke would rush out of the window if I had the climate control on and not on recirc. But in this car it's as if it's always in recirc mode? Anyone else notice this?

I've quit smoking for the most part,(thanks Mercedes) but I remember it would just hover around no matter what fan speed setting I used if I was at a standstill or low speeds. Has new cabin filters and no climate error codes.

kajtek1

I never smoke, but in your case I would make sure you have fresh air flap open.
Start the car, turn the blower to higher speed and blow smoke at passenger side windshield gutter. This is where fresh air inlet is.
I wonder if you can test smoke sensor there as well.
Suppose with heavy smog the car automatically switches to rec and carbon filters with message in the cluster, but the only report I heard about the feature come from Eastern Europe.
Air outlet goes to the rear and via the trunk you have flappers on sides behind the bumper.

THEhomelessONE

When I changed the expansion valve I had all the plastic covers off and the flap worked. Don't remember if it uses vacuum or a motor but maybe it's getting weak. I think there's a smoke machine in the shop, I'll try to find it, thanks.