whats an "evap" on a car? i know someone knows

So I got one plug in left on my wiring harness just hanging around on my harness, its a blue plug, the guy who made my harness said its for evap, uhhhhhh. What and where is that! (St205 motor in 88 all trac) thanks.

I assume its a JDM ST205 motor/harness?

Evap is short for Evaporative Emissions System. In your case, there is a solenoid that is on the JDM ST205 that is attached to the evap canister in the engine bay. For your swap, just put a 1kohm resistor in the plug to fool the ECU into thinking something is there and then just run the evap system like it was stock on your ST165.

-Charlie