i have an 98 civic DX coupe with a set of DC headers. because the headers dont have a cat in them like the factory dose the cat is now located under the car like it is on the 99 si. the factor set up has a o2 sensor in front of the cat and one right after the cat dose it need to be set up the same, or dose the second o2 sensor now go before the cat?

 

i have the same thing as you. 96 civic Ex with DC headers. i never really looked for the O2 sensor. but 1 is ON my cat. the other, really havent bother looking for it.
i will now though

 

If you dont want a cel you need one up before the cat and one after it.

 

okay thanks man that's what i thought but for the some reason the person i bought it from had the bung right in front of the cat. also do you know if i can splice into the o2 sensor to lengthen it?

 

yea you can splice it.

 

will i need to solder the lines together or will wire clamps work

 

just cut, add 18 gauge wire, solder, shrink tube it and your done

 

thanks bro

 

np. its easy as hell.

gl.

 

i wouldnt ever use butt connectors, wire taps always solder and heat shrink your connections.

 

i cut the plug for the downstream o2 sensor off at the harness. what gauge wire should i use to reconnect the plug the the harness?

 

X2



And to OP you want to use atleast. 18 guage

 

sorry "OP" ????