Noticed this plug/sensor came lose today after driving into a car wash. Could someone please let me know what it is? Driveability feels exactly the same as before.

Thanks

 

without getting a real good look it,and the location..your guess is as good as anyone else's.
Have you went under the car and checked to see if the other connector to that is near that unplugged connector yet??

PS: State your CAR too..I am assuming FD as per your Sig.(guys do have a tendency to not update their stuff on here!)

 

O2 sensor plug? How the hell did it get disconnected from up top then. Anyone ever have this happen?

 

If you have an aftermarket exhaust and 2 bungs,and aftermarket ECU,Guys will leave the stock O2 in to fill the hole,like a plug.
I know that is what I did for my Haltech.
The bonus for this is that you can just pop the stock O2 out for dyno,keeping your wideband hooked up in the car.

 

Makes sense, but I have a stock ECU with a M2 DP, stock cat and RB dual tip.

 

Fixed last night. Thanks to Mr Dale Clark for identifying it as the O2 sensor.

I fished the plug out with a dry cleaner coat hanger hook after spotting where the O2 sensor sits on my M2 DP; took some time to locate it but after that it was pretty straight forward. The harness connector doesn't really secure the sensor plug too much it seems.