I just put in a cabin air filter in my '04 Mazda 3. Unplugged battery, removed fuse box, opened filter cover. There was no filter set already there so I cleaned out a couple leaves and put in the new cabin filters. Everything seemed to go great.

Afterwards, I noticed that if I have my fan air set to top/face level and not floor/bottom, I still get a some (small) percentage of air from the floor vents. Perhaps this was occuring before I added the filters, not sure.

Could I have done something that caused some percent of air to leak to the floor vents when the fan is set to top/face? Knocked something, pushed some foam around, etc.? Or is this normal or perhaps was a pre-existing problem? I don't know exactly what kind of mechanism controls this or where this mechanism is.

If this was an existing problem, that's fine... but I figure if it's something I did and can fix relatively easy, why not try.

Thanks!

 

I get some air at the floor as well, its not alot but there is a bit, same with defrost, when its on full defrost there is a bit on the floor. Think its rather normal and nothing to worry about.