O2 sensor question (02 passport)

I went to AutoZone to get a read out of the error code on my 2002 Honda Passport (3.2L 4wd auto), and they told me it was O2 sensor 1 of 2. This is supposed to be located on the passenger side. Does anyone know if this is upstream or downstream, if this matters at all when it comes to ordering the actual sensor (I read somewhere upstream and downstream sensors are the same), and where this O2 sensor would be located. They told me I could find it on the passenger side after the c converter.

Gotta know the specific OBDII code. You have 4 oxygen sensors on your truck. One upstream of the catalytic converter and one downstream for each cylinder bank. I'm still driving with a bad one on my 2002 3.2L rodeo, I just swapped it to downstream of the cat as they do nothing for fuel trim in that position :evillol: . I still have to get a new one from St.Charles to get my CEL to go out! You will have a horrible time trying to find an OEM replacement O2 sensor for a 2002 & AZ wont have them. New ones are around $106/ea from www.stcharlesauto.com which is the best price you'll find. All 4 sensors are exactly the same for 2002. The OEM's are denso and for some reason these specific sensors seem to have problems. My 2002 started with a P0155 = bank 2 sensor 1, O2 sensor heater malfunction (driver's side, upstream) and eventually went dead all together. I tried a "Walker" brand sensor, supposedly just like OEM, but the plug was different. I have to a new one soon as I'm due for state inspection :uhoh: .
G/luck
Joel