Yah so, looks like I've played with it one too many times and now its broken... I think. The screw spins freely in both directions and doesn't seem to change anything. I *think* this because when it was working and I would turn it to full rich the engine would start to want to die, now the idle and sound of the engine stays the same no matter how much I turn it or which direction.

Is this bad? Or should I just say "screw" it and not care

 

It's only an idle fuel trim without much range.
Maybe grab one next time you're at a salvage yard.

 

Yah I know its only for idle, and I figured it wasn't that big of a deal. Just wanted to make sure

 

It sounds busted. I'd disconnect its plug. The ECU will default to some value.

Or backprobe the output wire on the thing and watch the output voltage as you turn the srew. I think mid range is 2.5 volts.