My lexus Es300 engine light keeps going on

you got to put it in the computer sys (for car) your dealership should do that for you or any machanical place ..also that happens when your gas cap its not on right or mayb a sensor is bad

It means an emmisions system component is not operating properly. the code(s) need to be diagnosed and fixed. even if its the gas cap you still need the equiptment to clear the code..and get the light out.

Likely a bad oxygen sensor.

It could be an even cheaper fix.. It could be a loose or broken gas cap. Fiddle around with yours, or get a new one from a parts store and put it on and see if that does it. Best case you fix it yourself or blow $10-$20 for a gas cap.

How about you bring it to a mechanic shop, and they will tell you better than somebody on . for all you know, they could 10 year old answering this question.

No one really knows what is wrong with your car. Go to a dealer, independent shop or even a local auto store and they will be able to tell you. Some will even do it for free.

The dealership or any auto shop will be able to tell u what ''codes'' the car is throwing so they know exactly where the problem is. It may be free at some auto shops. You can also try renting a OBD l or OBDI l reader from pepboys or autozone. It should be just a deposit which u will get back when u return the thing & they will also tell u how to use it. Its just a little electronical thing u plug into the bottom of ur dash somewhere & it reads codes that u can decipher using a book or online somewhere.

Edit: the place u rent it from should also tell u if u need the OBD l or OBDI l depending on what year ur car is.