HelloCustomerand Thank you for choosing Just Answer. I will try and answer your question to the best of my knowledge and make sure you are 100% satisfied.
If you noticed the salt/sugar before you started the car, Then the gas tank needs to be drained and cleaned out.
If you ran the car while the salt/sugar was in the tank, Then you could have many problems come up and it can get very expensive. The fuel tank will need to be drained and cleaned, Fuel pump may need replacing, All fuel lines will need to be removed and cleaned, Fuel filter needs to be replaced, possibly fuel injectors will need to be replaced. Hope this helps.