I had a similar problem with my 98 ES300. The engine light turned on. Lexus also said it was the charcoal canister and "VCV Rail", also about $800. When I posted this problem at Edmund's site I got a reply saying to remove the EFI fuse for about a minute (engine off) and then replacing it. It worked perfectly, but weeks later reoccurred. When the light turned on a third time I immediately turned off the engine, opened the gas cap (to relieve the pressue), closed it, and started the engine. Problem solved (for now)! I've also since then replaced the gas cap and have had no more problems, but it's now been cool now for 6 months. Problem may arise now that we are beginning to get into the summer. One wonders why to replace both canister and vcv rail (whatever that is)? Will keep you updated