To remove the smell of gasoline from upholstery, make sure that the original stain has been completely cleaned up. Follow up by treating the place where the stain was with a substance that neutralizes or absorbs odors.
Clean gasoline from the upholstery by scrubbing with a solution of a grease-cutting dishwashing liquid and hot water until there is no more oily residue visible. Rinse the upholstery with clean water, give it access to fresh air, and allow it to dry. If oil is still present, spray the surface with rubbing alcohol until it is wet and allow it to dry.
If the gasoline smell is still present after the stain has been cleaned up, sprinkle the area where the stain was with a generous amount of baking soda. If there is padding beneath the fabric, rub the baking soda in to reach the padding as well. Allow the baking soda to remain overnight, and vacuum it up the next day. Repeat if necessary.
Coffee grounds can be utilized as a substitute for baking soda, using the same steps. An alternative method of deodorizing is to spray the upholstery with white vinegar until it is wet. Provide access to fresh air, and allow it to dry.