^^^ This. Used Wix in my 2006 Duramax as well. Stay away from the aftermarket oiled air filters out there. Everything I've seen reveals no benefits or gains in any category and usually leads to codes being thrown. Stock paper filter works just fine. If you open the air box regularly you can remove the filter..a few light taps to knock out any debris and dirt and extend the life of the filter a bit. My .02I've always been partial to WIX filters
Amazon.com: WIX Filters - 46930 Heavy Duty Air Filter Panel, Pack of 1 : Automotive
Buy WIX Filters - 46930 Heavy Duty Air Filter Panel, Pack of 1: Air Filters - Amazon.com ✓ FREE DELIVERY possible on eligible purchaseswww.amazon.com