[Bob B.]

I installed a cabin air filter on my 2011 Yukon, that should be the same as your truck. The AC Delco part numbers for the kit are 22759208PKIT for the standard filter, 22759208CKIT for the carbon activated filter. Dorman also sells a kit with a carbon filter as part 259201, 259200 for the standard filter. To access where the filter goes you have to remove the 'hush' panel under the HVAC box. It covers the box and the blower and goes from the right kick panel almost to the accelerator pedal. It was a few hex head screws holding it to the bottom of the box, the screws are located in holes on the bottom surface. Once you get that off, look for a rectangular double ridge molded into the bottom of the HVAC box just to the right of the blower. There is a tab with a screw hole right in front of the rectangle, that is for the filter cover screw. CAREFULLY cut the rectangle space out of the box, cutting between the ridges. I used a large and very sharp Exacto knife. Trim or sand the inner surface where you cut so the filter slides in easily. The filter is made to bend, you have to flex it around the transmission tunnel to get it in. Secure with the cover and screw provided in the kit. The end of the cover has a tab that goes into a slot in the HVAC box near the firewall, the screw goes into tab on the front with the screw hole. Reinstall the hush panel and you are done. Here is a picture of a filter kit installeded:

https://motogurumag.com/image/LnzjCM/

Some of these pictures may be helpful:

https://chevroletforum.com/forum/mis...hments&t=25469