unplugged

Hello, I have a 2000 CRV. I have an unplugged pigtail that I can not figure out what it is supposed to go to! it is diving me nuts! Anyone know where it might go? Thank you for any help!

Sorry if this has been answered, I tried searching and didn't see anything. I just noticed that there is an unplugged connector by the radiator fans. They fit together, but wasn't sure if they were meant to be connected. There hasn't been any service on the coolant system, so I don't think...

This is for a 2007 CRV L. I changed the engine air filter and left the connector on top of the tube unplugged. My wife drove the car about 15 miles and then told me about the emission control indicator light being on. Is this connector just a sensor and does it matter that we drove the car with...