88 HF engine harness..

Ok so, I have an SI interior harness, but I couldnt put it in because my DX (and hacked) engineharness wouldn't match..So I was in the junkyard today looking for some seat sliders for my new SI seats, and I found an 88 HF, I promptly took the engine harness, and I will be back for much more than that, its the first mpfi civic ive seen at any of the junkyards I visit...and it hasnt been touched under the hood. Anyway, I vaguely remember reading something about the 88 harness having an extra plug or something? Is this correct? I do remember unplugging one from a diaphragm on the throttle that I'm sure I don't have, would this be it?
And If it does have another plug, will this make the plugs notmatch correctly? Or just add more wires to the 3 main plugs?? I will repin if necessary, but I'd like to know beforehand...