Fuel economy issues

Come to think of it it looks more like it could be the valve cover, make sure that's sealing first before you take the intake off.

If the intake gasket is bad it will usually leak air and oil from the valley into an intake port. If you are seeing discolored gas and junk in your throttle body that means you need a new fuel filter and/or clean your gas tank and replace the in-tank pickup filter. What is this rubber boot you are referring to?