Just got a used dc sport header and bought a new high flow cat for a 90 civic Si. question is there is no bung hole for the o2 sensor. where should i tap it? bottom of the header or the catalytic converter

thanks

 

I see this turning into an "In da butt" thread very fast, I believe if you search you'll find that everyone puts the second bung closest to the same area as stock.

 

I did search and didn't find anything useful and i had hoped that people were oriented enough around here to use common terminology?

i thought about putting it in the stock location however i wasnt sure how the ecu would interpret two cyl's info verses 4

 

Its for a d16a6 correct? If so, is it a 4-1 or 4-2-1. If its 4-1, put it in the stock spot, at the top of the collector. Does everyone agree? Ryan

 

the obd0 o2 sensor doesnt seem to care if its tapping into 2 cylinders or 4. its a simple little bastard. dont worry much about that. just dont drill a straight hole and tap the tubing on the exhaust. you should get a nut welded onto it after you drill a hole. thats what i just did on my home made header......in the 3 inch downpipe(yes, i know thats a BIG downpipe......but man does this sucker rip in the top end)

 

its a 4-2-1.

 

Well if you wanted to put it where DC put it you would put it almost to the end of the header right before the cat. Also do what he said above drill the hole and have a nut wleded on and also use a lot of antiseaze!! Just make sure you only keep it on the threads though. When I got my last parts car it already had a DC header and it took quite a bit of BS to get the old O2 sensor out since it was rusted in.

 

Yes i will have a proper threaded bung welded into the pipe, i just don't know where.

if i put it at the end of the header before the cat. do i need a different sensor? or will the current o2 senor have a long enough wire to reach?

 

The downpipe is the correct location for the Bung on a DC header. DC places this at the collector end.
You will need an extension cable for the O2 sensor back to the stock connector.

 

thank you

is this extension cable something i need to make or do they sell them?

 

you should be able to use any type of electrical wire to extend the O2 cable. i would recomend insulated wire around the same gauge as stock. I have also heard that if you don't replace the wire with stock honda wire you can get a ecu error code (just something i heard, of course there is no theory behind that and was just probably blindly thrown out there for suckers like me) good luck

 

I would put it up closer to the head..

The O2 sensors on DC are pretty far down and have a tendany not to heat up as well muh as they should. And as a ersulst mnay times don'w pass smog tests..

 

how can you put it closer to the head? it would only read ONE cylinder? you'd be basing your entire fuel curve on it. i would hope you chose the one that was running optimally...

oh and everyone keeps saying dc places here? if dc placed how come there isn't a bung hole???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StlSupra &raquo;</TD></TR><TR><TD CLASS="quote">oh and everyone keeps saying dc places here? if dc placed how come there isn't a bung hole???</TD></TR></TABLE>
I dont get wehat your saying?? The DC header that I have DOES have a bung hole but like I already said its down on the downpipe right before the cat. And what he is saying is correct it wont stay heated up down there not giving you the best reading thats why I am going to go with a 3 or 4 wire O2 sensor that way its heated. As for extending the wire if you talk to them at DC they have them my header came with the extension so that it would reach all the way down to it but you could make one yourself as long as you get the plugs. But if you do make your own make sure the wire is the same gauge as stock and that you use "Sheilded" wire.

 

hmmm i bought mine used and it doesn't have a hole. Now i am wondering if its for the right car?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StlSupra &raquo;</TD></TR><TR><TD CLASS="quote">hmmm i bought mine used and it doesn't have a hole. Now i am wondering if its for the right car?</TD></TR></TABLE>
Who knows?? Are you sure that for a fact that it is an actual DC header?? Maybe its not CARB certified?? If it is it will have all the numbers right on the top of the header. All the info should be on a plate on the top right by the head.

 

yeah there is a dc sport tag stamped on the top of one cylinder and a carb # stamped on another. in later years honda do they naturally put the o2 in the cat? maybe this header is for one of them?

 

Well I dont know what years they started putting the O2 sensor in the cat??? I actually didnt know that they did that at all?? I know that up to 95 I know for a fact that they were in the exhaust manifold but not sure on the 96 and up?

 

I think it depends on the model..

for the 97 dx hatch there is an o2 above the cat and below, and the cat is directly infront of the block..

 

well i'll take a picture of it first but i am going to have a muffler shop weld a bung on it and hope it fits

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Outsane &raquo;</TD></TR><TR><TD CLASS="quote">I think it depends on the model..

for the 97 dx hatch there is an o2 above the cat and below, and the cat is directly infront of the block..</TD></TR></TABLE>
As I Already had stated I wasnt sure about the 96 and up.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stlsupra &raquo;</TD></TR><TR><TD CLASS="quote">well i'll take a picture of it first but i am going to have a muffler shop weld a bung on it and hope it fits..</TD></TR></TABLE>
I would test fit it before you go and spend money on getting a bung welded into it....Well unless you can get it done for free that is.

 

i thought about that, however since this is my only running car at the moment i can't have it apart then run up to the muffler shop