Petrol Smell

[mohsin1122]

Hi
I have honda City 98 and recently swapped my engine D15 non EFi with D17 EFi
Fuel tank and fuel line also upgraded to support EFi
But from last few days there is too much petrol smell inside of car. I checked with mechanic and there is no petrol leakage from any where he also told me that as my car is converted to efi and it miss some air line or same sort of thing due to which gasses are created inside of petrol tank and cannot properly exhaust and cause the smell and according to him there is no way to get rid of it ☹️️
Can anybody suggest some solution or mechanic
Current EFI fuel tank used is of Honda city 2000