It dosen't come with a "recharge" kit, but it can be purchased seperately. I have left over K&N cleaning/oil which I plan on using if I don't get an AFE or AEM dryflow filter for my S&B CAI. Cleaning depends upon driving conditions...such as if you drive alot in dusty or dirt roads the more often you should clean it. I know with about 5k/little over a year of use on mine it is looking a little dirty with on road/city driving. I don't like to worry about the "too much" or "too little" when oiling the filter so I have planned from day one on getting an AEM dryflow filter once mine was dirty. My S&B was one of the first production run ones which had a few fitment issues, but I got for dirt cheap compaired to the other CAI's for the titan...so even with purchasing the Dryflow filter I will have spent less than an AEM/AFE/whatever.
I had my SES light come on once for a "too lean" condition after having the S&B installed for about 1000 miles, but I'm not sure if it was related to the S&B or a system hick-up; either way it hasn't returned.
RPM Outlet has them for $230 shipped.
http://www.rpmoutlet.com/nissan.htm
I had a good shopping experience with them when I got my JBA exhaust.