o2 sensor question?

[boostedb16]

i just bought a greddy header for my 98 gsr motor. my stock manifold has a o2 sensor in the bottom part of the manifold and in the cat. my car is a 96 civic with a obd2 to obd1 harness and a chipped p28. the header i bought dont have a o2 bung in it and someone told me that i dont need the o2 sensor in the header since i have the one in my cat. please help........

[xbn83]

You have one where? Before or after the cat? I'm pretty sure you need one before the cat, OB1 don't need the one after the cat.

[boostedb16]

i have one in the middle of my cat.

[xbn83]

In that case, sorry I don't know the answer!

[boostedb16]

thanks anyway.

[boostedb16]

does anyone know what size thread a gsr o2 sensor is.

[xbn83]

This one I know, 18mm x 1.5

[boostedb16]

hey man thanks and +1 for you.

[scttydb411]

you need the primary before the cat...the one in your cat is the secondary and is no longer being used since obd1 doesn't look for it. you'll need to add an o2 bung in the end of your header of just before the cat somewhere.

i tried calling you back...sorry it took so long. i assume this is the question you were trying to get a hold of me for. in the future feel free to ask your question on my voice mail if i'm unable to answer. i'll be more than happy to call you back w/ a message and if i don't get you i'll leave a message with the answer.

[boostedb16]

thanks scott. yes that was the question and i went a head and had one welded in.