Cumfigali

Check Engine light. The orange diagnostic symbol.

Hi All, hopefully someone can help here. Re-fulled the other day shortly after the CEL came on. Pulled over and checked everything over, all seemed fine. Did a quick google and loose fuel cap came up as one of the causes. Checked that and it seems tight, usual woosh when opening which would indicate a good seal. The light has went out a few times but comes back again. Does the system look at this periodically? Or does something run intermittently which would throw up the fault? Have also seen something about a charcoal canister, where is this located? Does anyone have fault code for fuel tank pressure/leak. Looking to get and OBD 2 reader. Does anyone have part number for fuel cap Lexus or Toyota equivalent. Many thanks