Regarding the OEM Air box mod, someone (and I'll do it if time permits) should consolidate into an easy step by step post. But for now, see these links... The mod is ~$5 for the two caps needed and time wise it took me 1-2 hours, but I like to take my time when doing unfamiliar mods
Josh's original thread - http://www.clubfrontier.org/forums/s...ead.php?t=4672
Useful link on an Xterra site which Josh found (Post #8 on the thread above), has some good details - http://www.xterraownersclub.com/cgi-...;f=70;t=000190
My thread, which may have some additional details, start from about post #7 onward - http://www.clubfrontier.org/forums/s...ead.php?t=5183
Josh's original thread - http://www.clubfrontier.org/forums/s...ead.php?t=4672
Useful link on an Xterra site which Josh found (Post #8 on the thread above), has some good details - http://www.xterraownersclub.com/cgi-...;f=70;t=000190
My thread, which may have some additional details, start from about post #7 onward - http://www.clubfrontier.org/forums/s...ead.php?t=5183