where does this plug go?

[RDSFSU2004]

I have a '90 Corrado G60. I just rebuilt the engine and labeled all plugs and wires. When I had everything plug in I came up with one plug left unplugged. It was the last one that I unplugged when I took the engine out so I only labeled it head. I have looked everywhere for the other side to plug it into and can't find it. The wires that run to the plug are black and brown with a two prong female plug. It is the last thing I need to finish the job. If anyone can help out that would be great.

[Russ]

where exactly is it at? if you can describe the area or have pictures i can go look at my rado