Well i just changed my check valves and pcv valve hoping to fix the problem but my driver side a/c vents still blow much stronger on the far driver side and gradually gets weaker as it moves to the passenger side. Any help would be appreciated.

 

Might be a restriction in the tubing somewhere..... only trouble is, gotta pull the dash to find out.....

might be able to see something if you pull the fan.... but, I wouldn't hold my breath on that.