Your posts are getting confusing , you said that it guzzles gas when you drove it , if its got an evaporation style leak and it was going threw a significant amount of fuel then you would have a very strong raw fuel smell , if its got that kind of raw fuel leaking or fuming out from anywhere its very dangerous .
The air bag module system capacitors will hold a charge and possibly still fire after battery is disconnected , if you are messing with wiring and not sure what you are doing , disconnect the main connector to the air bag .