We purchased a house from family in august, and have recently started using the fireplace insert. We were unaware that it has a catalytic converter, until today when we removed the steel/ cast iron plate in the top of the firebox to straighten it, as it was warped rather badly (we didnt cause it to warp). The cat was plugged completely with ash and we brushed it with a soft brush, vacuumed it, and then used low pressure compressed air (20psi max) to clear the remaining ash. It is now reinstalled in the stove and has a nice hot fire going. I know it has never been cleaned (until now) or replaced, is this reducing its efficiency or hampering the stove's performance at all? The damper can now be completely closed, where before it had to be left open partially (bypassing the cat). The cat is located where it cannot be seen with the doors closed, so I cant tell if its glowing or not. There is a slight amount of white smoke coming out of the chimney. Thanks!