[tirwin]

That is the O2 sensor connector. They are known to break and crumble.

There is a user on here... Name escapes me right now... That makes a replacement.

Edit: As soon as I can think of his name I will post it. By the way, the green wire is actually 2 wires in one. It is a shielded wire. The outer portion is grounded and acts as a shield for the low voltage signal carried from the O2 sensor to the ECU on the inner wire. There is also a myth that air is carried inside the wire but it's not. That may be true in other O2 sensors but not these.