I have a 97 civic dx with a b16a2 (2000 si) and im throwing a cel code for a o2 sensor my stock harness has 2 plugs one for the down pipe and the other i dont know. where does the secound o2 sensor suppost to go? I have been getting different ideas with no luck to searching.

O2 sensor
1. header
2. before cat?

02 sensor
1. before cat
2. after cat

PLEASE HELP

 

Edit:

One on downpipe, one on the cat.




Bottom exhaust is supposed to be the Si/Ex exhaust.

 

ok so then i need a new headers because the headers on there irght now do not have a hole for a o2 sensor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yeah_its_fast &raquo;</TD></TR><TR><TD CLASS="quote">ok so then i need a new headers because the headers on there irght now do not have a hole for a o2 sensor
</TD></TR></TABLE>

I got ahead of myself and answered to quickly, please re-read my post.

 

ok thank you im studing it really hard to see where those are suppost to go

 

There is no O2 senor on the header of a b16a2 i believe. I think it's before the cat and after the cat. Someone correct me if I'm wrong.

 

there should be one in the manifold(downpipe) and one in the cat. not after the cat , in it. and if your under the car looking up , you might even miss it , cause its goes top down into the cat.

 

ok thank you. yeah my cat is another problem I dont have a cat on the car. so im trying to be inviroment friendly and put a cat back on but wasnt sure about the o2 and i didnt know that the si or ex cat has the hole on the cat which fixed all this. Thanks again and Happy Turkeyday

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ondahush &raquo;</TD></TR><TR><TD CLASS="quote">There is no O2 senor on the header of a b16a2 i believe. I think it's before the cat and after the cat. Someone correct me if I'm wrong.</TD></TR></TABLE>

Just look at the bottom pic of the diagram posted.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cranny &raquo;</TD></TR><TR><TD CLASS="quote">there should be one in the manifold(downpipe) and one in the cat. not after the cat , in it. and if your under the car looking up , you might even miss it , cause its goes top down into the cat.</TD></TR></TABLE>

I think this one is correct there is one on the down pipe, and one ontop of the cat.