Pop the hood and take a good look around. Then kick the key to on, off, on about 10 times to ensure the system is pressurized, then back off. Stick your head back under the hood. Follow the likes from the fuel rail to where they become hard lines by the drivers strut tower. In that space you will likely find a pinhole leak that is filling the plastic loom cover the fuel lines. You probably don't see it because it's filling the loom and drooling out somewhere out of sight.
On the TB spacer, very few can document any performance gain from it. Most can though document how a gasket in that area blows out and coolant begins leaking into the throttle body causing at worst your motor to hydrolock and a tow home. If you want to keep the TB spacer, I'd suggest blocking the coolant ports at the LIM to keep any coolant from being able to be a future problem. Your best course of action though is to take it off and sell to an unsuspecting newbie. Just don't tell us you did that, because we don't condone it.
