I purchased my 2016 Silverado about 3 months ago. But about few weeks ago noticed white powder coming out of the vents. I What do you think it is? The dealership told me it was because of a faulty sensor gone bad. I googled it and says it could be aluminum oxide .

 

cocaine from a past drug runner?

 

That's what I was thinking, did you "feel different" on the drive home?

 

check the cabin filter