Okay so i got photos now to explain and you can see better what my problem is. my issue is my extensions don't fit perfectly
(but 1 extension fit snug to the cat's 02 sensor, but it was new)
another problem is my 02 sensors need to be both male plugged into the 02 sensor harness.
(wire harness, sorry don't know name. it's under the distributor) So please have a look, thanks guys.

So this one is of the 2 females where the extensions should plug in.
(these 2 are right below the distributor)



this photo is one of the females from above and the 02 sensor extension male to where it should plug in.



here is the cat's 02 sensor which is a male and the 02 sensor extension that's female.

(another photo showing its the cat, zip-tied it so it wouldn't drag on the road)



here is the header's 02 sensor which is female and the 02 sensor extension that's male.

(another photo showing it's the header)



Okay, so once i took these photos the 02 sensor on the cat fit perfect with the 02 sensor extension (then again, we had bought it new since the old one stripped). But, the header wasn't so easy as the cat and they didn't seem to fit (from the dx header, not new).
In conclusion i've came up with a few ideas why i'm having an issue:

1)my header's 02 sensor should be male so the extension can plug.
2)my 02 sensors (the plugs) are dirty/broken maybe?

hopefully you and a few other might be able to help me out with fixing this asap, as well as maybe an alternative if there is no solution.

Thanks,
JayVee

 

you don't extend the header's O2 sensor.

extend only the cat O2 sensor. Leave the header O2 sensor plugged into the bung on the 4th cylinder exhaust runner, and directly into the engine harness next to the distributor.

 

okay, i'll look into it tomorrow in the morning. thanks if something happens i'll update.

 

well didn't get enough time in to do it. woke up even more sick but i will tomorrow in the afternoon. hopefully things work out fine.

 

okay the headers 02 wont reach the bung.
it's not long enough to reach it.

 

That's odd. Can you take a picture? Perhaps a new one will have a longer O2 sensor wire harness.

 

let me re-clarify what i said, sorry.

when my old DX header was on the 02 sensor from the (top) header reached perfectly to the wire harness/bung/hook-up.

now that i got this EX header, the 02 sensor from the (bottom) header won't reach without the extension
(i assume it looked too far to reach)

and i'll get the pictures up tomorrow.

EDIT: 1 thing i realized when i went to buy my new 02 sensor at the honda dealer, the lady didn't ask me what submodel or if it was for the cat / header. wierd, i'll see what happens but i'll get the pics up tomorrow.

 

I told you already not to use that O2 bung... use the one in front of the engine, not the one under the car.

 

but the header is a EX header, so it's on the bottom. or is there one on top?

 

Right there on the side of the cylinder 4 runner