2004 subaru misfire 4 please helpp!!!!!!

[jjtraps420]

So my car is misfiring on cylinder 4 but it's not continuous and it only occurs when I either pump gas or the tank is halfway or at the 1 mark not sure of the gallons or what the correct term is lol but it also did come up with this other code that I'm not sure what and where it is but I do have reason to suspect that it is the fuel pump assembly or the fuel pump itself but I need to be sure has anyone else ever had a problem like this??? The other code for it is PO183 Tanks anyting helps!!