first off read this,http://hondata.com/techclosed.html as i will be referring to alot of terms in that article.


now, as we all know the first gen b16 comes with a manifold that uses 2 o2 sensors; one sensor per pair of cylinders.

the main answer that most of us have come to as the "right" way to install an aftermarket header is to put 2 o2 sensors in
the respective places on each primary. in the end this way looks ugly, and must be extremly restrictive since the o2 head
takes up most of the primary that its in. i have just recently aquired a wideband controller, and will be using screenshots
of my datalogs for example.


now since i know you have read that articel on hondata i will show you what i have for a "good" signal






these 2 pics show the ecu learning and tuning on its own. the high and low points are 14.9 and 14.0 on this particular
datalog

now theres 2 ways i have found that will do this for you.

one of those is retaining the stock o2 setup. the ecu will tune per pair of cylinders and everything will be good
the only other way i have found is to run one preferbly shielded wire to the ecu and run both o2 wires to it.

now the voltages we are messing around with are EXTREMLY small (0-1 volt) so you need to make sure that the signal is getting
to the ecu without any noise or loss of signal.

i have tried running sensor 1 and sensor 2 by itself, and the graph ends up something like this..



it would never go back up and would stay at 10:1 for my car.i have a feeling that expereience will vary on this based on the
long term fuel trims that were previously there. the main point is that the ecu will NOT tune the afr for you.

all this is on a chipped PWO, that has a stock fuel program with tweaked ignition tables.


everything so far is not perfect, tho.

im still working out issues with part throttle accel and afr after shifting.
this could be becasue of the way my o2 is setup or it could always be like this; i dont have any stock setups to plug my wideband
into at the moment and see whats happening there


this is on a partial throttle loading i.e. going up a hill on the freeway. the afr remains perfect until the load climbs. at
that point the afr goes leaner and leaner, but does not jump. that makes me think that the ecu is not controlling it and that i
might be able to fix it, but i still need to do some research with these issues


this is on throttle tip in right after a shift. at the moment i am most worried about this and loading the motor at partial
throttle. on my motor which is 13.3:1 comp i could have some serious issues running the motor this lean for long periods of time
i dont think that a stock motor would have much issues, tho. at some point the ecu goes to open loop, and if i get worried i
punch the gas and itll kick it right down to where i tuned for (13.5:1 afr)


so, until i find a better way of doing it, i would reccomend 1 of 2 setups for anyone playing with it;
a heated 02 at the bottom of the header with a shielded wire for the signal running straight to the ecu, and then running both 02
wires off the ecu to that.
or setup 2
im currently running a zeitronix wideband 02 which has a narrowband out on it. i ran that wire directly to both wires on the ecu,
and with that i have gotten some fantastic gas mileage (240 miles and 1/2 tank left on my built b18c)


since all this is just my experience, i would love to hear other ppls "fixes" for running aftermarket headeders on obd0 ecu's

thnx for reading and a big for HT because without this board full of newbs and stupid questions i wouldnt know half of what i do

 

Nice info, I have 2 bungs on my header but plan to go OBD 1 with the new motor so thats my way around it.

 

man, now you got me rethinkin my header purchase

 

So, its not true that by running 1 o2 sensor will make your car run bad?

 

Let me throw my 0.02 into this subject matter.

With my B16 before I rebuilt it, I had one O2 bung on my DP. This was connected to both O2 sensors inputs to the ECU. When this was done the car did not run that good.
Later I tried to run only one O2 input, with this the car overheated on me. Then I had to disconnect the O2 sensor completely and the car was fine. So later I had the muffler shop weld another O2 bung onto my DP so I can have 2 o2 sensors for the 2 inputs that the ecu needs.

Since these are not hooked up by cylinder pairs it never ran correctly and finally decided to discount it entirely.

I had read somewhere about this subject matter before where they discuss running it in open loop mode.

For me Open Loop Mode works best for my applications, and car has being running strong.

But this is interesting reading, since every persons ecu is different and everyone car is also. It would be extremely to say what works until you experiment it all.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kid-honda &raquo;</TD></TR><TR><TD CLASS="quote">Nice info, I have 2 bungs on my header but plan to go OBD 1 with the new motor so thats my way around it.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Waachback &raquo;</TD></TR><TR><TD CLASS="quote">So, its not true that by running 1 o2 sensor will make your car run bad?</TD></TR></TABLE> My car runs great with one o2 sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX T-Si &raquo;</TD></TR><TR><TD CLASS="quote">decided to discount it entirely.

I had read somewhere about this subject matter before where they discuss running it in open loop mode.

For me Open Loop Mode works best for my applications, and car has being running strong.

</TD></TR></TABLE>

I put a DC header on mine, and had some major bogging from the two o2 wires spliced. So I ran mine in open loop mode for 3 months... it seemed that after long distances of traveling on the highway the car would start to act funny. So, I just swapped to obd1, and used the signal o2 sensor like the obd1 cars look for. Now it runs flawlessly. I swapped everything from a 95 del sol Vtec. Now it runs perfect... Like the engine belongs?

Another option is that Hasport header. It is custom for the non obd motors and has 2 bungs on it.

 

You said:

so, until i find a better way of doing it, i would reccomend 1 of 2 setups for anyone playing with it;
a heated 02 at the bottom of the header with a shielded wire for the signal running straight to the ecu, and then running both 02
wires off the ecu to that.
or setup 2
im currently running a zeitronix wideband 02 which has a narrowband out on it. i ran that wire directly to both wires on the ecu,
and with that i have gotten some fantastic gas mileage (240 miles and 1/2 tank left on my built b18c)

I have a few questions...
How does setup 1 differ from setup 2 besides the O2 sensor itself? Do both setups yield fantastic gas mileage? Hondata says wiring a single O2 signal to both inputs on the ECU will cause it to run either too lean or too rich, but this isn't the case for you? My car runs really rich but when I switched ECU's to PM6 it ran cleaner (to pass smog), does this mean that the single O2 signal is adequate?

 

all this info is meant for people that have an aftermarket header.

hondata sys one bank will run lean becasue they are assuming your still using 2 cylinders to moniter the entire engine, when in fact with an aftermarket header your measuring the entire engine ouput.

by all meaans if u have the abilities to run 2 o2 sensors use it. but if u are forced to go to one and want it to run semi-well, try this method out.

BTW the obd1 conversion probably is THE best way to fix it, but i dont have the cash to put into an obd1 conversion yet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johnzm &raquo;</TD></TR><TR><TD CLASS="quote">BTW the obd1 conversion probably is THE best way to fix it, but i dont have the cash to put into an obd1 conversion yet.</TD></TR></TABLE>

Could I get a link to a thread and/or webpage that deals with how to do the ODB1 conversion?

 

I like converting to OBD1. way better. I have done both OBD0 vtec ecus with 1 o2 and both o2's. I have never had a issue running both wires to one O2 but if you do that I would suggest using it on a header with the bung at the bottom so it reads all the exhaust. if you want to do both O2's I would suggest either a stock header with both bungs at the top or go with the hasport header. it is real important to have one O2 read each pair of cylinders. oh another way is to chip it and disable one of the O2's. that works but all in all from my experience going to OBD1 is way better. runs better,idles better. better gas mileage,smoother powerband, better for emmissions. also the OBD1 dist is better cause it is not prone to vibrating loose the retaining screw and have the dist rotor come loose and stall your car while driving.

 

Good info. My PR3 is chipped and has disabled sensors, so I guess this includes the 2nd O2 sensor (pin 16?) Can OBD1 conversion be done with just an aftermarket OBD0 to OBD1 harness?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eda6 hb &raquo;</TD></TR><TR><TD CLASS="quote">

My car runs great with one o2 sensor.</TD></TR></TABLE>

Mine does too, but my gas milage sucks. Anyone else have bad gas milage because of this?

 

from the things ive seen, that voltage is extremly important and its real easy to mess it up

i unfortunatly let someone do mine the firt time, and he ran 2 wires together in the engine bay. that killed all chances of it working becasue the small voltage never got to the ecu.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX T-Si &raquo;</TD></TR><TR><TD CLASS="quote">Let me throw my 0.02 into this subject matter.

With my B16 before I rebuilt it, I had one O2 bung on my DP. This was connected to both O2 sensors inputs to the ECU. When this was done the car did not run that good.
Later I tried to run only one O2 input, with this the car overheated on me. Then I had to disconnect the O2 sensor completely and the car was fine. So later I had the muffler shop weld another O2 bung onto my DP so I can have 2 o2 sensors for the 2 inputs that the ecu needs.

Since these are not hooked up by cylinder pairs it never ran correctly and finally decided to discount it entirely.

I had read somewhere about this subject matter before where they discuss running it in open loop mode.

For me Open Loop Mode works best for my applications, and car has being running strong.

But this is interesting reading, since every persons ecu is different and everyone car is also. It would be extremely to say what works until you experiment it all.</TD></TR></TABLE>

What is open loop?

 

to reelizimpo you can convert to OBD1. you need a jumper,obd 1dist and a 4wire o2 and just some time and wire and connectors.

to waachback you can get better gas mileage by tuning and also watch the way your drive. constant on throttle and off throttle gives bad gas mileage.

 

Yea I figured that, I was just wondering if running only 1 o2 sensor would cause bad gas millage. Thanks

 

yes 1 O2 can depending on where it is placed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by smart monkey &raquo;</TD></TR><TR><TD CLASS="quote">yes 1 O2 can depending on where it is placed.</TD></TR></TABLE>

Where would correct placement be if only using one o2?

 

I like to put it at the bottom like how a OBD1 car is. this way it reads it all instead of just a pair of cylinders.

 

Sorry so perhaps sounding negative, but why bother?
OBD0 B16 needs two o2's. What you do to get around this still wont work as was intended.
I guess if you are buying a JDM engine it'll come with the manifold which has the space for two sensors. If you are using an aftermarket then weld that sucker up.

Why the heck would you want to run just one when its sooooo easy to do it properly?
Its cheap enough to make the yank manifolds compatible in the UK, it should be peanuts cost wise for you guys

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nominous &raquo;</TD></TR><TR><TD CLASS="quote">
Why the heck would you want to run just one when its sooooo easy to do it properly?
Its cheap enough to make the yank manifolds compatible in the UK, it should be peanuts cost wise for you guys </TD></TR></TABLE>

HE is referring to people using aftermarket headers, with the exception of 1 company, nobody makes a header for a jdm b16a with proper placement for o2 sensors, its not a simple as just welding a bung because most of these header primaries are not paired together like the stock header.

i have a ecu that eliminates the 2nd 02 sensor, it was the cheapest way for me to resolve my problem, (zdyne) it will be for sale soon.