Problem apparently began when we noticed gas fumes inside the cabin. Mechanic said we had leak on top of gas tank and that fuel lines were corroded. We had tank replaced, fuel lines replaced ( did brake lines as well) Fumes were still noticeable, we took it back - they tell us that they need to replace “sending unit” and fuel filter. They did so. Fumes are gone but now in the first 10 -15 minutes after start up and driving - the car hesitates and acts like it is not getting gas for about a mile or so and then evens out again. We tried running a tank of higher octane fuel and fuel injector cleaner. No improvement. Also now engine noise is noticeable - never was before - in fact other than the gas fumes the car ran fine before we took it in for repair. any suggestions would be greatly appreciated.