Well i have a check engine light and i was assuming that it might be the O2 sensor but i got down to find it and replace it and i couldnt find one. I looked everywhere, manifold, cat, everywhere. I have the b16a motor in my car, does this motor need an O2 sensor??

 

What kind of car, etc? Also, don't assume it's the O2 sensor, do yourself a favor and check the code. Blindly replacing parts isn't really the way to fix things.

 

It is a 94 civic hb with a b16a swap. when i bought the car the guy said it was throwin the o2 sensor code so thats what led me to belive that it was the o2 sensor. But just curious, does OBD0 have any o2 sensors? I know that OBD1 has 1 O2 and OBD2 has 2.

 

Yes, most had a single O2 sensor, but the PR3 and PW0 ecus are looking for 2 sensors in the exhaust manifold.