Hey, I have a 96 hatch and have an extra primary o2 sensor layin around. The previous owner had headers for only 1 o2 sensor. I just bought the stock headers that has the second plug after the cat. I was wondering if it is the same as the secondary and that would work for my secondary o2 which is after the cat? I have been told that they are the same, and from others you have to have the secondary sensor. Because I know that the rsx o2 sensors are different then each other. Thanks

 

I dont think they are. Im not 100% sure but im pretty sure they are different.

 

They are interchangeable as far as functionality is concerned.

 

I thought they were different, but when i was looking to buy both the primary and secondary on http://www.sparkplugs.com and other sites selling O2 sensors both part numbers are the same. Check for yourself to be sure. Just do a quick yahoo search and compare part numbers.