I changed O2 sensor and it's pigtail that melted after making contact with manifold, but this came unplugged from behind the engine and I can't trace it back to anything. All my O2s are plugged in. Please help I would greatly appreciate it. Thanks!!

 

What year is yours? I have an 08 and that does not exist on my car. Does your car run ok? Any lights on the dash?

 

It's an 07 GT. It's running ****ty, no cold air from ac and the plug shares the same wrap as the downstream O2 sensor.