Alright so the black wire from the 02 sensor fell out of the clip but is still attached to the sensor. I tried to jam the wire back into the clip but i still get the check engine light is there any chance of me saving my 02 sensor and 100 bucks?
I'm not sure what type car you are driving, but on Ford's the black wire is the ground wire if I remember right. If you have to you can go to a junk yard and cut the plug off of a salvaged car and splice it onto the existing sensor using male/female connectors then either tape them up where they won't ground out or cover them using a heat shrink, just be careful not to get it too hot and melt the insulation on the wires. I've used universal sensors before where you cut the plug off your old sensor and spice it onto the new one without any problems at all. The universal sensors are available on eBay for about $20. if you need another sensor and can get a plug from another car.