My stock headers had a crack so i replaced the headers and now cel is on and idk where to connect 1 of the o2 sensor i know 1 goes in the bottom where dose the other one go?

 

How about this? What car?

 

1998 Civic d-series

 

That helps NOT AT ALL. What engine is in it?

 

d16y7

 

And you have no catalytic converter now? Did you replace it with an aftermarket header? Please provide more detail.

 

yes the catalytic converter is on the stock header which was removed when i put the headers on

 

You're confusing me. Yes you have a cat or yes there is no cat?
Read this.
http://www.d-series.org/forums/natur...y7-header.html

 

pretty sure he's saying he took the stock manifold with the cat in/on it and replaced it with an aftermarket one which doesn't have one.
at least thats what i got out of it.
its header.
did you get the right one for your engine?
the CEL at my best guess is because the o2 isn't hooked up and after it is theres no cat so you'll still have it.

 

Since it is a y7 right.

What brand header or a ebay one? Does the new header have a bung for an o2 sensor?

If that header has a bung that is the primary o2.

Now did you put in a cat in the stock location that the y8 would be if the car was an ex?

If so you need to hook up the secondary o2 there.

Or if no cat now you need a test pipe, maybe for a cat delete, or if you have a tuned car, you can override it in a tune.

 

Override!? Jeez. If he has a tuned car the ECU would be OBD1 which would not even be looking for a second O2 sensor.

 

Just a shot in the dark, lets see what he says he did.

 

To use that header your going to have to weld in a cat after the header that has an 02 hole. Then you can extend your second 02 sensor and place it in that hole.