If your vehicle is showing strong smell of gasoline inside the cabin, here are the most likely causes and the parts you'll need to fix each one.
Degraded or pinched fuel injector seals allow raw fuel to leak onto the hot engine block. The HVAC system then pulls these strong fuel vapors directly through the cowl and into the cabin.
The fuel pump is often located directly under the rear passenger seat. If the lock ring or gasket is damaged, or not seated properly after a recent fuel pump replacement, raw fuel vapors will vent directly into the cabin interior.
The EVAP system is designed to capture fuel vapors and route them to the engine to be burned. A cracked canister, stuck purge valve, or loose gas cap will allow raw fuel vapors to escape into the atmosphere and enter the cabin.
Rusted metal fuel lines, degraded rubber hoses, or a leaking inline fuel filter can drip fuel under the vehicle. The resulting vapors easily seep through the floorboards or get caught in the vehicle's slipstream.
Severe rust, corrosion, or physical impact can crack the fuel tank or the filler neck. This causes a constant fuel leak that produces a strong odor, especially noticeable right after filling the tank completely.