LexusFan09

Hey guys my 97 lexus es300 has 200,000 miles on it. It Runs good. I have no problems but sometimes when my gas is under the half mark the check engine light will come on for awhile but then it will go off sooner or later. Is that maybe a big issue? Could that mean I need a pressure sensor or something. Some advice would really help. Thanks

Rollin'ES3

Id scan it to be sure. You could sit here all night and guess, but scan it and see what code it gives you...we'll go from there once you get the code

brucelee1

iTrader: (2)

Get a code. Likely, it is the gas cap that needs to be replaced.

angmedic91

iTrader: (5)

I would agree with Brucelee1, sounds like maybe your gas cap is having issues. But, to be sure, like Rollin'RX3 stated, scan it for the code to get a better diagnosis. During the summer here in So. Cal., I was getting a checking engine light sporadicly when the tank went below three quarter mark. I would clear it by removing the negative cable to the battery. Then I realized I was topping off the tank till the gas was at the cap. Would do this on my other car, 1991 Nissan Sentra. Got my Lexus in April of this year and didnt realize these cars have sensors for everything. Topping it off caused a pressure shift. Now, if I dont top off and the gas goes below the three quarter mark no CEL. Plus, the heat expanding the gas in my tank didnt help matters either.

ALarsh

Replace your gas cap. I just had to do this on my 97 not so long ago.