My black connector that connects the oxygen sensor to the car's wiring melted. Is the sole purpose of this connector to just connect the oxygen sensor, or does it do anything with voltage and stuff? Can I just use a plastic wiring connector to connect the two wires?

 

yeah it has to do with voltage and stuff, from the O2 senser. not sure about resistance of the crimp connectors, but at this point you don't have lot of options.

 

Uh yeah.. put the crack pipe down and just use a butt connector to crimp them back together. Life will be good again.