Lexus Troubleshooting Questions? Ask a Lexus Expert
Do you happen to have the "p-codes" that were scanned from the on-board computer?
Ok. Unfortunately, without the p-codes, there is absolutely no way to know for sure where the problem lies. And taking a guess and be correct would be impossible as well. Hopefully I can give you a little insight...
If there are no performance or drivability issues, then more than likely the problem lies in the EVAP (emissions control/recovery) System. Unfortunately, there are literally dozens of parts/sensors/solenoids in the EVAP System. To get us started down the correct path, we'd need those p-codes. You can have these p-codes read FREE (except in California) at any local "big chain" part store (ie. AutoZone, PepBoys, Advanced, etc). These p-codes will point towards the faulty part/sensor/solenoid and from there we can make the correct repair. There are a few different "known issues" and Technical Service Bulletins for items in the EVAP on this vehicle.
As for resetting the light- you can, however, if the problem was not addressed or repaired incorrectly, the light will return within 50-75 miles of driving.