A long time ago I bought a replacement o2 sensor and never installed it. Now I can't figure out which one it is and I want to replace it. It is made by Walker, part number on the box is 250-23090 - does anyone know which one this is? I havae checked everywhere and it seems to me that they sent me the wrong one, or changed the part number. In their catalogue, the replacement for the 96 maxima doesn't match the number I have. Thanks in advance

 

the front 2 are the same the one on the catalytic converter is smaller than the front 2.

 

Um i dunno but check your ECU and it should tell you which oxygen sensor is bad. It told me I had a bad rear heated 02 sensor so i knew exactly which one it was code "07-07".

 

what does that code mean when it says "Bank 2"???

 

you have left bank and right bank.. I think the right bank is the front o2 and the left bank is the rear o2. this is on the engine not behind the converter..