I've been searching for a good price on these for a while. Here is what I've found.
Part Numbers
OEM 89467-48001
Denso 234-9009
OEM from Lexus, $150
http://www.factorlexusparts.com
http://www.factorylexusparts.com/servlet/t...AIR-FUEL/Detail (link may not work)
Denso from Rockauto.com, $136.79 (at time of posting)
www.rockauto.com, search for part in their catalog.