Hello everyone!

My check engine light has been on, i got the code and it's "Primary Oxygen Sensor".

The problem im encountering is the location of it! Most diagrams show that's it's on the headers. I have aftermarket headers and intake so it's not there. I bought the car like that. Me and my brother have been looking for one near that area and haven't found it. However we found one right before the cat. We can see it when we look staright down from the top of the engine, it's sticking out of the pipe. It's probably 10 inches before it reaches the cat. After that we tried to look for one behind the cat, but we couldn't find one. There's suppose to be another one correct? The secondary one that's suppose to be behind the cat?

Do you guys think we're looking at the primary? My brothers friend says if you changed your headers to aftermarket ones, then you'll only have one instead of 2 so i dont know what and who to believe!

btw
I have a 97 civic 2 door ex coupe, engine code is d16y8
Id appreciate any input! thanks!

 

Primary is located in exhaust manifold, secondary is located at top of catalytic converter right behind connection to exhaust manifold.94

 

We tried looking for it in the exhaust manifold, we cant find it. I have aftermarket DC headers. The only O2 Sensor I found the one on the pipe about 5 inches bofore the CAT. Do you think that's it?

 

According to my Haynes there is one mounted in the front/top of the cat itself, the pix indicates it is a few inches behind where cat is connected to exhaust manifold/pipe, [with the two spring loaded bolts] just behind drivers side axle.94