[Shotimes] 02 Sensors

[Jonathon Beisler]

I purchased new Bosch Plugs and rented the tool yesterday so that I can get back under the car tomorrow.  The reason that I asked before about how to pull the 02 sensor off is because the size of the nut or whatever you would call it in this application around the base of the 02 sensors in the car is rather large.  It is not the standard size of most 02's I have replaced before or the size of the tool that I rented..  Has anyone had this experience or was I looking at it wrong.  Is there an outer nut that the 02 screws into?  Am I blind as well as stupid?  Some help please.
Also, I want to flush the radiator this weekend as well and I have been told by friends not to use the regular drain because large items can clog it up.  Should I just use the lower hose coming out of the engine?
Thanks again, Jon