First, thanks to TQ2K for posting the DIY for the Valvetronic

It says to remove the filter housing you need a 36mm 6pt. socket OR 24mm 12pt. socket.

I'm not sure why he wrote that. It's a 24 mm socket either way, correct?

http://www.xoutpost.com/articles/x5/...lvetronic.html

Also, I learned that when you order the plastic cover for the filter (11427521353), it includes both the plug for it (11427518083) and the large O-ring for the outside.