Universal o2 sensor?

Greetings,
My 2001 Tundra 3.4 2wd has an OBD code that indicates rear o2 sensor needs replacement... of course this is the more expensive of the 2 sensors... while searching for a compatible sensor I found a listing for a "universal o2 sensor" (I'm guessing that means good for front or rear?) ...can anyone advise if this is an acceptable replacement sensor or to be avoided?

 

Don't, universal are generic sensors that require splicing your old plug on.

Denso or NTK would be ones that I'd use.

 

Front and rear are definitely different. I would definitely say get denso brand if you don't want a headache later on. If you have one going out it might be good to knock out all of them. (Does the v6 have 2 sensors or 4 I'm not sure). The sensor shouldn't be too expensive I don't think. The denso downstream is $48 on rockauto. Link
The upstream for the v6 appears to be pricey at $120 for denso.

 

This is one of a couple parts you absolutely do not want to use aftermarket parts for on your truck. Buy Denso brand, pony up, it's going to save you money and hassle later. You definitely DON'T want to use anything that splices into the cable, you'll be chasing gremlins a few weeks, months, or years down the road.

 

I know they're pricey, but accept no substitutes. Better yet, change both upstream sensors at the same time.

Denso 2349001 if Auto

https://www.rockauto.com/en/moreinfo.php?pk=870733&cc=1375354&pt=5132&jsn=408

Denso 2349003 if Manual

https://www.rockauto.com/en/moreinfo.php?pk=870696&cc=1375354&pt=5132&jsn=409