90-91 DC header question

I just bought a DC header for the 90-91 Integra but when I got it the o2 sensor is in a different spot, down by the collector. On the 90-91’s the o2 is suppoosed to be on the top part of the header and on 92+ it’s down by the collector. I thought it was a mix up at first and someone put the wrong header in the wrong box, but after checking the stamps on the header (AHC9003) it is indeed for the 90-91.

So how is that going to work? I have a single wire non-heated o2 sensor that is supposed to be located close to the head to get warm enough to get a proper reading. So if I use this header won’t it be too far away from the factory location and not get hot enough to read correctly? I mean with it being in the same location as a heated o2 sensor but yet it is not heated I don’t seee how it could work correctly? I’m sure it has to make a difference. Let me know, I’m not even sure if I want to put this header on now.

I have one on my car and i havent had any poblems. Since you only have one O2, and its the one wire one your prolly not going to notice any problems. Maybe throw a code once in a while. Unlikly thou. Now if you had 2, 4 wire O2’s it would matter more.

To get your old O2 out you may have to heat up the manifold, if your not buying a new one.

They sell O2 extenders on most wiring site’s, if not its not to hard to add more length, just do it the correct way with shrink wrap and solder.

I have a new o2 sensor so I don’t need to worry about it. Also, the header came with a extension piece for the o2 sensor already. I just can’t believe they would move the sensor to a location that the sensor is not designed to work in. This is the first header for a 90-91 Integra that is like this, every other one always has the o2 in the factory spot.

I still don’t like the idea of this. Can anyone who has had this header on their 90-91 let me know how it did?

DC is a reputable company. I dont think they would make a header that would cause problems. Mine is carb legal, Is yours?

Yeah, I know their a reputible company. But I’m just not seeing how a non heated o2 sensor can get a accurate reading by the collector.

Also, I just looked at it and it had no carb badge on the header itself. I thought all DC headers were carb legal though. Not that I care, just wondering.

I have a DC header with the O2 sensor at the rear and have never thrown a check engine light.

My advise to you 1. install the header 2. run the car and alow the header to heat up and blow off the smoke. 3. install the O2 sensor and reset the computer. If you instal the O2 sensor first you run the chance of fouling it.

gs,ls,rs??

my friend has a 93 integra…he doesnt have no power windows no sun roof no power locks and he wants to know if its ls rs or gs…its a b18a1

RS is the only Integra that does not have a sunroof.

dude why u tripping? if its on the collector u should be happier as all u do is cut and extend to that and u have a better reading of air to fuel ratio anyway like 92+ cars.

obd0 02 sensor only tells it that it has fuel or some sort and understand that the 3rd runner u thinking it should be on does not read all 4 runner DUH!.

this is normal on all no name brand and some cheap companies etc. Will run fine even if its on just the 3rd runner as u think it should like the stock 90-91 header. but u will have a bad emission smell.

notice on stock 90-91 header the 02 sensor location is also near the portion where the downpipe mates? it actually runs thru all 4 runners this is how u will not get a check engine light.

I know because i have stock, no name header and DC from a 92+ where the collector has the 02 sensor bung.

i prefer it at the bottom to read more better dont u? like 92+ cars…makes more sense. but then again its only a 1 wire fuel reading sensor like…

goodluck man…

AND I HAVE an RS with everything manually. no sunroof and its a 1991. hope that answered u

i have a 93 gs without a sunroof, so you never know.

I’m tripping because it doesn’t make sense to me. So is my understanding of how the o2 sensors work wrong then? I mean if a non-heated o2 sensor can be down by the cat why does it need to be heated on the 92+ cars? I always assumed it never got hot enough down there for a non-heated o2 sensor to function properly, hence the reason why all cars with 02 sensors there are heated.

Kinda pissed about this now also. Only reason I got the DC header is because I have a 90’ and it’s hard to find headers for them. If I would of known that the o2 sensor is in the same spot as all other 92+ Integras I could of just got one of those because you have so many more choices. I could of easily got something with a 2.5" collector to match my cat.

The O2 sendor is heated on 92+ cars because they have different emissions (OBD1) controls. 90-91 Integras are OBD0 and do not need a heated O2 sensor. The O2 Sensor is moved on the DC Header for estetics.

Your key word “assumed” says everything to me. Pleaase do some research.

i had a 90-91 dc 4-2-1 header and my o2 sensor was correctly placed. you definitely have the 92-01 header no matter what the part number says.

[QUOTE=Integpk;2087299]I’m tripping because it doesn’t make sense to me. So is my understanding of how the o2 sensors work wrong then? I mean if a non-heated o2 sensor can be down by the cat why does it need to be heated on the 92+ cars? I always assumed it never got hot enough down there for a non-heated o2 sensor to function properly, hence the reason why all cars with 02 sensors there are heated.

Kinda pissed about this now also. Only reason I got the DC header is because I have a 90’ and it’s hard to find headers for them. If I would of known that the o2 sensor is in the same spot as all other 92+ Integras I could of just got one of those because you have so many more choices. I could of easily got something with a 2.5" collector to match my cat.[/QUOTE]
obd1 cars do NOT have a heated o2 sensor. obd2 cars do. btw the whole point of a heated sensor is so that the sensor heats up faster to give the ecu a more accurate reading sooner. if it’s non heated it’ll just take longer for the sensor to heat up. since obd2 is so strict about emissions it needs this feature.

just extend the wire and be done with it. everything will function properly.

some pics of my header for proof.

Exactly how that picture is for all no name brands and dc header for the 90-91 header. O2 sensor is on runner 3 and only really catch emission of that.

I had a no name branded header with o2 sensor bung located exactly like this and when it was time for smog here in cali i didnt want to waste time and take off and put my stock header where all four runners meetup at the end.

Anyway with the header i still had a slight smell from my exhaust. Gone to smog and fail by few numbers and the guy told me put my stock back and come back and thats how i knew i passed.

So now i have a dc header with same bung located on 3rd runner but i screw it shut and extend the wire down to the collector where i made a new hole for it, and now it works as good as stock or better. Problem solved for me and i can bet anyone with a no name or dc header with o2 sensor bung on 3rd runner is going to have a richer smell on the exhaust regardless…

notice runner 2 is there but with all the pressure pushing out really runner 3rd is probably the only main one sensing it most. Probably not to a point where anyone would care much of a notice, but if u are about emission,gas proper mix air fuel etc or be as close to factory setting then EXTEND wire down with new hole in collector in replacement for o2 sensor if using aftermarket headers.

They must of changed them then and yours is just the older style. Because mine is most definitely for the 90-91 also but the o2 sensor is in a different spot. I mean the actual header itself is stamped as a 90-91, box says 90-91, it comes with the extension wires and directions for 90-91, plus it is the same length as my obx header for the 90-91. Doesn’t sound like a 92+ header to me. At the very least it would be a different length if it was.

Well anyway, I went ahead and put it on. I guess I was worried about it because I was wrong about how the o2 sensors worked. Funny though, I’ve heard that from more than a few people about it not being a good idea to move your o2 down there. Oh well. It’s throwing a check engine light right now but I did like advised and didn’t put the o2 sensor in right away. I’ll go for a little drive later to burn off any crap in the header and install the o2 sensor. Hopefully it works as well as you all are saying.

Make sure you reset the ECU after installing the O2 sensor to clear the check engine light.

Integpk do you wanna sell the obx header?

Just install it!!!

do what 2ndJenn said by reseting the ECU after you install the damn sensor. Just install the DAMN header its a DC Sports header for gosh sakes DC Sports is a badass company and very reputible so install the damn header get better performance like im sure you wanted which is why you bought it an who gives a F*** where the damn sensor is…DC Sports put it there for a reason and gave you the extension for a reason…it will still work perfectly fine, so install the damn headers already an stop bitching if you want to bitch then return the damn header already…hope you dont do that though cause DC Sports headers are freakin amazing!!! sry if i came off like a dick but this post is getting annoying an dumb lol :bang:

:manual:

Ok, how about you chill with this attitude.

You just joined not too long ago and already calling a thread “annoying an dumb”.

Not a good way to start off on this forum. :ban: