Here's another cause for the evaporative emissions codes indicating a failure to purge the vapors in the tank:


http://lexus.sewellparts.com/images/...000/172790.jpg

Part 23818 - the little plastic box that connects to the hose that some people report can pull off, in my case one of the fitting nipples that slides into the flex hose broke off. JB-welded it back together and it is fine (purchased the replacement anyway). Maybe time to check motor mounts - although I have no other signs of worn mounts.