The one's on ebay are not inferior but are OEM denso 02 sensors. They are what the dealer will sell you for 3x the cost. I just got one 3 weeks ago and was identical to the one the dealer had at 1/3 the price.

 

When I search Denso Lexus O2 sensor, I get universal sensors, NOT oem sensors... when I search Lexus o2 sensor, I get a bunch of generic parts... not saying they aren't on there, but I don't see them...

 

Ok, so I decided not to go to the dealer yet for the sensor...Denso's online site is selling their OE sensor for 89.20...I think this might be the better route to go besides finding one on ebay... yes? And if I'm gonna order from there, I was thinking of picking up new sparkplug wires also while I'm at it...So, new plugs, new wires, new sensors...hmm...anything else?

http://www.densoproducts.com/results...ctCategoryID=2

 

Try here:-

http://vi.ebaydesc.com/ebaymotors/ws...tones&caz.html

 

If you check the first sticky in the second gen GS section you can find most of your answers as well as stickys in the ES section. The torque spec for the plugs are 13 ft lbs and the drain plug is 29 ft lbs for my GS430. Might be the same for you.

 

Forgot. Watch which O2 sensors you buy. The cheaper ones you have to splice on your old connector while the more expensive are plug and play.