The stock airbox has a 'basket' that sits over a foam on both the top and bottom half. I guess the foam is for sound inulations, maybe heat.
The problem is this foam on the bottom half of my box was beaking down in to powder like pieses. These pieces were cloggin the hell out of my K&N. If you have a paper filter dont think it is a big deal. However on the foam was suck in the filter really bad.
I removed the foam from the bottom (top seemed fine) thenbanged the filter out and put it back in. I noticed the pep was back into my m44.
-Dave