After visiting Autozone for them to give the CEL code of P0446, I decided to replace the gas cap on my 2000 GS300. After replacing the gas cap, I removed the neg. lead on the battery for approximately 30 seconds and replaced it. The light stayed off for approximately 3 days and over 600 miles. It then returned again. Kind of strange that it would go for this long. Any help would be appreciated, as I know this topic has been explored a great deal.