Corolla with intermittent code saying System Too Lean (Bank 1) P0171 after refueling. First i noticed that there is slightly stronger fumes when i refuel then the code will illuminate ( Code not always comes on). It happens with half tank and up and always improves with lower than third of tank. I never top off and i just replaced gas cap but didn't help. I read here a lot and checked Fuel trims and found they go higher positive every time i refuel. I have some data file to share Here Please help.
Thank you in advance.