Hi - I have a 2000 ES300. I've had it for about 8 months without any problems, until recently.
About 1-2 months ago, the check engine light has come on. I've reset the light three times, but it continues to return. I've replaced the gas cap - lights return. All times, it has been related to the Evaporative Emission System. Codes have been P0440, 0441 and 0446. They are annoying, but I understand that they should not create a problem (other than being unable to pass the emissions test).
The recent problem was that is started running extremely rough two days ago. The engine code is P0305 - Cylinder 5 misfire. I checked the connection - all seems OK. I replaced the spark plug - problem is still there. I'm going to swap an ignition coil with one of the other cylinders and see if the problem moves to another cylinder.
Other than this, does anyone have any suggestions? I think that beyond this, I'm in over my head.
Thanks - Chris