2001 Lexus is300. After filling up, difficulty starting

[zirjeo]

Will not start right away after filling up, this is the only time it has trouble starting, otherwise runs fine. Have to wait several minutes and step on gas for it to 
start. Doesn't matter if filling to full tank or half tank etc. Also the CEL is on. P0440 evap code. I replaced gas cap, tried replacing purge valve and 
hoses in area, replaced fuel pump strainer as it was very dirty(did not replace the pump or filter), replaced overfill check valve, charcoal canister valve. Also tried using HEAT to try to remove any water and clean fuel injectors. 
Any other ideas?

[TrevC]

Was the filler cap a geniune OE part as I know this is the usual cause of the fault where it doesn't seal correctly

[zirjeo]

Not OE I don't think just picked up from advanced auto.  But if this was issue wouldn't it always have issues starting, not just after pumping gas?  And would this even cause it to not start after pumping or just throw on CEL?