Yes, the louvres are clear. I also took out the housing that transfers the air / heat from the burner up into the drum. It is clean. I see no restriction anywhere. What's baffling is how much of a difference it makes - panel on it could take 3 hrs for a load to start to dry (even without the vent hooked up). Panel off, load is completely dry in a 1/2 hr (even with the vent attached). It seems simple, that logically there must be a restriction, but, I've had this thing apart down to the bones and everything's clean.