Hi everyone!

I have been getting a rear O2 sensor fault for many months. I went to go replace it only to find what seems to be another type of sensor. This has been there before i owned the car so i have no history of this maintenance. I was under the impression that both the upstream and downstream sensors are identical. Perhaps the original threading was damaged and they put in another type of O2 sensor that works with the Maxima system. Any ideas as to what type of O2 sensor this is and if i can just purchase this specific type again? Any help would be greatly appreciated!

1996 Nissan Maxima
278K
All stock.

 

Welcome to Maxima.org. It looks like someone welded a different size bung onto the exhaust pipe. I can't identify the sensor. I can tell you the downstream sensors use a different type plug as compared to the upstream sensors. The tool to remove a Maxima 4th gen sensor is a 22 mm or 7/8 inch.

 

Iirc depending on the date of manufacture 96 came with two different thread sizes on the downstream.

 

Is the type of O2 sensor that is currently installed shown in the following link?


http://www.carid.com/1996-nissan-max...-21099922.html

 

That would be the one.

 

Outstanding. That sure does look like it's the correct one. I'm going to have to verify the harness but it looks good. Thanks for all the help. The human connection is still better than a computer!

 

Just got mine from Rockauto for $25.

 

I've bought a lot of parts from Rock along the way.. No bad experiences.

 

Question about the rear (after cat) O2 sensor..
I've had a code for this one for several months and haven't gotten around to change it since I didn't think it was as important as the other O2 sensors which affect fuel economy moreso and how lean/rich you're running. How important is changing this rear sensor/what happens if I don't address it? There's a lot of rust build-up there. Thanks.

 

Nothing happens, the downstream sensor only measures catalyst efficiency. If you need to pass inspection or want the engine light off you should change it.

Sent from my XT1060 using Maxima