Which sensor is which or does it even matter? One of them is on cylinders 1 and 3, the other on cylinders 2 and 4. Which one is the primary and which is the secondary?
from what i remember the actual o2 sensors are identical but the wiring needs to go to the right part of the manifold or else stuff will suck. and IMO those sensors should be replaced immediately if they came off one you imported from japan. The car will still run, but you’ll be hard pressed to pass emissions. also, what year is you car and what ecu are you running?
you can run only one like regular ls teg 02’s on it and just when ur wring the ecu pinouts t the secondary 02 pinout to the primary… worked for me…
Why do the sensors need to be replaced? Why would they be bad coming from japan? Engine should have less than 20k miles on it and the sensors look ok and they have never been removed from the motor…
This is a 90 integra non-OBD with a Pr3 ecu. I have the stock ehaust manifold that takes 2 O2 sensors. My guess was that the pimary sensor is on cylinders 1 and 3. So far it seems to be ok. I just wanted to confirm this before i go for a smog check. I guess nobody knows.
Correction…
If you’re running the stock PR3 ECU, you will need BOTH 02 sensors plugged in or you will have bogs and check engine light on…You will need to add the other 02 sensor to the ECU plug…the Primary 02 sensor goes to C16, and the Secondary 02 sensor goes to C8…
Good Luck,
-Jeff C.
even though its low milage in japan, it can be sitting for a couple years, seriously… mine were bad… regular same year integra ones will work for it though…
-Toby