bad on gas help

i have a 88 supra 7mgte that is getting verry bad gas milage and throwing codes 43 and 51 gas is real expencive and i dont know what else to check new plugs wires no egr or charcole canister by the way. gas milage is about 8mpg not even running it hard it also has a bad gas smell but no fuel leaks.

No duplicate threads please. This is not the correct forum for maintenance issues anyway.