so here's the deal, i have noticed that everytime i fill up at the gas station, m car runs pig rich as soon as i pull out of the station. doesnt matter where i go for gas. i only use a few differnt gas station, i'm very picky. i know this happens to subbies but never heard of it with an evo. also i get a CEL and the code reads as an o2 error but i have a simulator that should fix that problem. i'm stuck, i need so advice

 

are you tuned?? reflash, SAFC, AEM?? more info on mods...if any?? what octane??