Rattling O2 sensor

[flyinghigh54]

I have had this annoying rattle for years now, just recently I did some investigating and found it to be that the 2nd O2 sensor. I just passed smog just fine so i don't think it is bad. I tried tightening it but no luck.I took it off and shook it and it is something internally...... and the car ran with no rattle when it was taken out

I have no idea how to buy an O2 sensor is seems to easy to be right..

Is this what I should be getting?
http://www.drivewire.com/vehicle/gmc-yukon/oxygen-sensor/#2001

thanks for any advice!