2016 F150 sport, when I have the air conditioning on and the recirculating button pushed why do I still smell the stank exhaust from the truck two cars in front of me burning raw fuel or the guy smoking a cigarette next to me? Could it be the blend door actuator not working? I hear no clicking or popping when I to turn it on or turn it off but it’s definitely venting air from the outside. If I have the fan on low while I’m on the highway it’s blowing air at me like it’s on high.

 

I'm assuming you have EMTC (manual controls) in your truck. The "blend" door, or as Ford calls it, the Driver Side Temperature Door (actuator is Item 8) , controls the temperature of the air. The Air Inlet Door (actuator is Item 3) controls where the air comes from (fresh or recycled).