so im looking into buying a new header-the DC 4-2-1 stainless one piece. i have a b16a first gen obd0 in my 90 CRXsi with the ceramic 2 piece 4-2-1 and want the stainless one piece- will it bolt up perfectly? will there be any complications? also since my motor is obd0 it has one o2 sensorr right? or is it different for each header/year/obd whatever? im confused.

 

please help!

 

as long as its a b series header it will bolt to the head fine. Is your front X member notched? If not you may need to do this for clearance...I did.

I am using a DC one peice (Del Sol aplication) and it fits fine save for the cross member notch...it bolted directly to the stock exhaust with no modification...

I will recomend a Del Sol eader because I know that works (make sure it if for the Bseries Del SOl)...Im pretty sure you will have no probs with 99-00 si, GSR etc but I wont say 100%...

my header was only equipted with one 02 bung. you have several options here...
-convert to single 02
-purchase a header with 2 bungs...several companys make b series swap specific headers
-or have another o2 bung welded in...this is what I did...any capable exhaust shop should be-able to handl this with no prob.

 

its not notched....but will i have to for sure?

 

I did...you could by an aftermarket one...up to you.