Ok I just got an 2000 civic ex with a obd1 b16a(jdm) gen II swap, the car runs fine and everything but it throws a couple of codes 1 and 23 which I believe is o2 primary sensor and knock sensor, I've researched a lil bit about the knock sensor, but where is the o2 primary sensor located? And since its a jdm b16a gen II swap, what o2 sensor is compatible with it? One from an ek civic si? Also the car has no cat, just a test pipe so I dnt kno if that has to do with anything. And how should I fix the knock sensor in this specific set up? Thanks guys

 

primary 02 is right before the cat, you can use the one off your old motor if you still got it , if you are running an obd1 ecu test pipe won't throw any codes, if you are obd2 then it will cause a cel

gl