Anyone have "good luck" with a particular aftermarket brand O2 sensor replacement (back sensors) for a LS400 ('98). Is so, please respond with the brand and place of purchase.

Also, when one "goes bad" is it a good idea to go ahead and replace both rear while it's "on the rack"? Or, is it not likely that the other may "blow" soon.

 

I replaced mine with generic ones from oxygensensors.com - $100 for two main sensors. I wouldn't bother with secondary sensors, they dont do anything useful.