Mazda6 vomits gas out.

Question

2006 Mazda6 2.3L engine.
Mazda6 will not let me fill gas even tho the tank is empty. If I force fill, the gasoline bubbles back out with a lot of air.

Answer 1

The engine light is not on?

I would say there is something wrong with the EVAP system it won't let you fill up gas because there is built up pressure in the tank, there is most likely a clogged pressure hose or solenoid valve that is not opening to let the pressure out.

or something wrong with the filler neck 

see picture below 

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