just had the same thing happen to me. my son borrowed my car and put in hi test gas( no need for that in my 2000 olds alero) had the same code. car was running fine .my manual said if you change brands of gas this might happen i took the gas cap off and put some grease on the neck filler and on the inside of the gas cap. i did fill it up with regular gas. i drove it the next day and the light went out, the same thing happen with my wife’s car (2004 buick lesabre) drove that for a couple hundred miles and the light went out. as long as the lights not blinking there is no major problem-- hope this helps --best of luck