Is it possible to wire both the o2's so that they function as one or is there a way to eliminate one o2 sensor but still have the car run stoic? Reason being for aftermarket headers, there isnt a dual o2 hook up but the b16a has a primary o2 and a secondary o2... Thanks for the help

 

I am researching this hard and heavy myself. My understanding the only way to do it and not have drivability issues and poor milage is to do a ODB1 conversion, and that is what I am still figuring out.

 

That's the one major problem I have with nonOBD ECU's (in all my experience they're just soo ******* picky with O2 senors, you're motor will flutter sometimes if you have the primary and secondary flipped, etc.)... It's not like an OBDII car where you can plug in an oxygen sensor and zip tie it up somewhere... There's not really anyway around it and if I do this swap I normally just wire in both... It takes bungs getting welded in which I don't really like but the only other way is to chip your ECU... There's tons of proggies out there that eliminate the secondary oxygen sensor which is really the way to go but then again I hate just about every single chip made... Whenever possible I normally just convert the car to OBD1 and run a 4 pin oxygen sensor... Yes it is a little more work but it's really the way to go... Hope this helps... Just my $0.02

Here's Will's FI Rex's harness that I just finished converting to OBD1 for his FI setup... The engine harness wiring is all done but Scott (CrazyCompression) and I still have to finish up some boost controller and ignition stuff...

 

Yes but trying to figure this out, besides the 4 wire O2 sensor and buying a new ODB1 dizzy what else needs done (outside of the obvious adaptercable for the ECU.) and will the maps be right. I have to be able to pass emissions with this thing.

 

Yea, that's really about it, I did my first conversion about a year ago and making the jumper actually took me longer than the harness... The oxygen sensor is the main conversion along with either an OBDI or OBDII dizzy (I normally run the OBD2II single connector ones just cause I like stuff clean)... If it's a stock motor you can rewire out the resistor box and go with OBDI/II high impedance injectors and connectors (cleans up the wiring a bit) but like on Will's harness above I left them in and kept in the resistor box as we're running low impedance 900's... I normally swap the fan switch to the newer thermostat mounted style (looks cleaner too) but requires a new thermostat housing... As for the way the motor runs, as long as everything is wired correct there's no CEL (I've never had one) and your motor would run just the way it would in say an EH, etc (but if you've got a built motor or something along those lines then you'll have a fun time passing emissions anyway)... We've actually leaned out the mix with Hondata on some built NA setups in the past (nothing special, CRVTEC's 12.5:1 making ~230whp) to pass emissions, and it to has worked... Just doesn't work when you have an OBDI computer in an OBDII chassis and they try to plug in a scan tool, hehe... If you ever run into any problems let me know...

 

no if you try that it runs like crap and sucks gas.

 

well I have a PM5 I can pull the connectors from for one end of the adapter, if I buy an ecu and get the cut connectors I have something to work with, $250 lowcash racing wants is pricey. since I need to buy a Dizzy and ECU to convert.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by virginia_dude &raquo;</TD></TR><TR><TD CLASS="quote">no if you try that it runs like crap and sucks gas.</TD></TR></TABLE>
Are you refering to me or are you talking about running only the primary oxygen sensor on a nonOBD setup???

 

on my ls/vtec i've always run a pr3(2 o2 sensors req) and just split the wire from one o2 and sent it to both pins. never threw a code and always ran fine. some people do say it runs like **** but i've never had a problem. ran it like that all-motor and never had a problem either.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kataku2K3 &raquo;</TD></TR><TR><TD CLASS="quote">
Are you refering to me or are you talking about running only the primary oxygen sensor on a nonOBD setup???</TD></TR></TABLE>

Sorry I guess I typed that in not realizing what thread I had open. My bad. Had two windows open and got them mixed up.

 

haha, it's all good... Either way I didn't care, just wanted to make sure we were on the same track... Peace

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by justinh595 &raquo;</TD></TR><TR><TD CLASS="quote">on my ls/vtec i've always run a pr3(2 o2 sensors req) and just split the wire from one o2 and sent it to both pins. never threw a code and always ran fine. some people do say it runs like **** but i've never had a problem. ran it like that all-motor and never had a problem either.</TD></TR></TABLE>

I did that too, but as soon as I added the second O2 done properly with 2 bungs in the primaries, my car ran noticeably better with improved mileage and throttle response.

 

Either use your stock headers and do not try to wire both 02's together it will never work! You could drill in to a new header but then if that doesn't work your out a new header . Just convert to OBD1 Its so much easier cheaper, and its smog legal then. Not to mention, it will be much easier to fix.

 

i you want a temp fix dont plug in any sensors it will run rich though

 

just curious why an entire engine harness was created to convert to obd1?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">just curious why an entire engine harness was created to convert to obd1?</TD></TR></TABLE>
What do you mean by this... Sorry I'm a little slow, hehe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 87sivtec &raquo;</TD></TR><TR><TD CLASS="quote">

I did that too, but as soon as I added the second O2 done properly with 2 bungs in the primaries, my car ran noticeably better with improved mileage and throttle response.</TD></TR></TABLE>

Did you do this on 4-2-1 headers or in two downpipes of a 4-1 which I was told doesn't work.

 

I am told as long as you run one O2 sensore on 1or 3, and a second one on 2 or 4 since they are controlled in pairs and you need to see one of the two to get a reading. This should alow you to run a PR3 or a PWO ODB0 Ecu , have a 4-1 header, AND have it run as it should.

 

you can rip all the o2's and go rich . I know also if your o2's sensor arn't working it cause VTEC to fail sometimes, or the majority of the time. Don't waste the time drilling holes in your headers! just convert to OBD-1.

 

Well there is the cost of a ODB1 distributer that I don't have laying around, the 4 wire O2 sensor thats not already laying around, The ODB1 ECU thats not convieniently laying around, nor are the adapter cables or ODB1 pugs for the O2 sensor and distributer laying around............Maybe its the bucks for all those things making me want to drill holes and weld bungs if it will make the parts I have already be happy together.

Not to sound touchy but that adds up to a lot of money I don't have convieniently laying around. Particularly if I want my Skunk2 stage two cams.

 

na that's cool I don't blame you it is a little expensive.

Good luck on getting it all working!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Undrgrndhaqer &raquo;</TD></TR><TR><TD CLASS="quote">Is it possible to wire both the o2's so that they function as one or is there a way to eliminate one o2 sensor but still have the car run stoic? Reason being for aftermarket headers, there isnt a dual o2 hook up but the b16a has a primary o2 and a secondary o2... Thanks for the help</TD></TR></TABLE>

Like other's have mentioned, you can't wire the 2 sensors together. O2 sensors work on voltage which the ECU reads the values so by connecting them together you are changing the voltage to where neither one will be correct ever. The OBD1 conversion is a drastic step to eliminate the secondary O2, if you have other reasons to convert then that's cool but for just that reason I would reconsider your options.
The beat thing to do is to have the secondary O2 mounted after the primary one either on your header, cat or exhaust - just depends what you want drilled really. Any muffler shop should be able to make a hole and weld on a threaded nut that will allow you to mount the secondary O2. I've seen this done numerous times with great success.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECVillain &raquo;</TD></TR><TR><TD CLASS="quote">

Like other's have mentioned, you can't wire the 2 sensors together. O2 sensors work on voltage which the ECU reads the values so by connecting them together you are changing the voltage to where neither one will be correct ever. The OBD1 conversion is a drastic step to eliminate the secondary O2, if you have other reasons to convert then that's cool but for just that reason I would reconsider your options.
The beat thing to do is to have the secondary O2 mounted after the primary one either on your header, cat or exhaust - just depends what you want drilled really. Any muffler shop should be able to make a hole and weld on a threaded nut that will allow you to mount the secondary O2. I've seen this done numerous times with great success.</TD></TR></TABLE>

Well thats not completely right. ODB2 cars have a primary and a secondary O2 sensor. The B16A1's two O2 sensors each control a pair of cylinders each (what the hell was honda thinking) were all the others balance the whole motor. But has anyone taken and put each of the 2 O2 sensors into one downpipe of each of the two pairs and had it work right, I know it should work, but has anyone done it.