Okay ive got a 1st gen b16 in a 91 civic hatch....I just got my DC 4into1 header and it only has one bung for the 02 sensor...my guestion is do i have to tap a bung for the second or is there a way i can only run one...Also if i get the computer reprogramed to run with out the o2's is that bad for street use or what...thankx for any help

 

I have a 99 si and the same dc 4 into 1. I currently put both o2's on but the
guy I bought it from only had the first one in with no problems and put a spark plug in the other hole to cover up the leak. I'll probably take out the second b/c of the gawd awful vibrating.

 

You will need to run both O2 sensors. One for each pair of cylinders 1-3 and 2-4. The ecu reads and adjusts the fuel to each pair accordingly. You can use a chipped ecu or switch to OBD1 which uses only 1 O2 sensor at the collector. With a chipped ecu that bypasses the O2 sensor, you will most likely see a lot less gas mileage and the driveability will suffer some.

 

one of the O2 sensors goes right after the cat converter, I have a half cut Sir with that part intact. So one in the header and one after the cat just like ODB-2 cars have. I don't have one feeding 2 cylinders and one the other 2, and mine is intact except for the front sheetmetal. All wiring cluster right down to the exhaust system is intact right back to the cut.

 

Is that a header or stock manifold? Stock manifold on a PR3/PR0 equipped car has two in the manifold.

 

when u do the swap u ain't required to use both this is optional as i have done three b16a to ef swaps

and i never used the 2nd o2

and i never got a check engine
first 2 swaps used a stock ecu
and this last using mugen program pr3

so it ain't really something to panic about

 

ok, I have a B16A1 first gen too. Its been swaped into a 93 hatchie
When I bought the car, it always had a check engine light on.
I've checked it and it pushs out codes for my O2 sensors. Now I also have DC headers and a chiped ECU. I noticed that I only have one O2 sensor too. I like to know...I need to change this O2 sensor soon cause my gas mileage totally sucks. The problem is I DON'T KNOW which O2 sensor to buy. do you guys know? Please help me out, its been 2 years without a new one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 87sivtec &raquo;</TD></TR><TR><TD CLASS="quote">Is that a header or stock manifold? Stock manifold on a PR3/PR0 equipped car has two in the manifold.</TD></TR></TABLE> I bought a SiR half cut, I had everything intact except for sheetmetal. My exhaust manifold has one O2 sensor, and the rear of the Catalytic converter has the other. Mine is 100% bone stock. Thats odd you have 2 when mine only has one. Point of note, mine is a first gen Civic SiR (true EF-9 has blue tag near left headlight) not the CRX and not the SiR II So I have the B16A1 engine and a Y-1 trans. Even have good CLuster and Automatic climate control.

 

Read this:
http://www.hondata.com/techo2problem.html

This article from Hondata helps explain the problem associated with the PR3/PR0 ecu and a single O2 sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by virginia_dude &raquo;</TD></TR><TR><TD CLASS="quote"> I bought a SiR half cut, I had everything intact except for sheetmetal. My exhaust manifold has one O2 sensor, and the rear of the Catalytic converter has the other. Mine is 100% bone stock. Thats odd you have 2 when mine only has one. Point of note, mine is a first gen Civic SiR (true EF-9 has blue tag near left headlight) not the CRX and not the SiR II So I have the B16A1 engine and a Y-1 trans. Even have good CLuster and Automatic climate control.</TD></TR></TABLE>

OK, need to correct my statement, I looked real close, Yes I do have 2 on the manifold, never saw the second one, but mine actually has 3 O2 sensors. 2 on manifold one on rear end of catalytic converter. What gives with that, its not shown on any of the wiring diagrams I have. But it is wired into the harness. Anyone else that bought a half cut Sir Notice this? Can anyone explain it to me.

 

Anyone know? please help***

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG6[B16A1 &raquo;</TD></TR><TR><TD CLASS="quote">]Anyone know? please help*** </TD></TR></TABLE>

just by a bosch o2 senor at autozone for you 93 hatch. and make sure you program keeps you in open loop so it only requires 1 o2 sensor. is your ecu a obd0 pr3?

 

You should use BOTH o2 sensors. The fuel trim is adjusted per cyl bank using both 02 sensor input signals. I tried one o2 sensor when I swapped my b16 in my 91 civic 5 yrs ago. Ran like sh*t. It has 2 for a reason.

 

I sort of covered a little of this yesterday too... If you've got time you might wanna check it out, though I don't know if it helps your situation...

https://honda-tech.com/zerothread?id=752990

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 87sivtec &raquo;</TD></TR><TR><TD CLASS="quote">You will need to run both O2 sensors. One for each pair of cylinders 1-3 and 2-4. The ecu reads and adjusts the fuel to each pair accordingly. You can use a chipped ecu or switch to OBD1 which uses only 1 O2 sensor at the collector. With a chipped ecu that bypasses the O2 sensor, you will most likely see a lot less gas mileage and the driveability will suffer some.</TD></TR></TABLE>

Heres a concept I want to ask people if they have tried, since cylinders are paired for computer the mixture should be the same in pairs, what it you put 2 O2 sensors reading one of each of the two pairs, Such as on 1 and 4 or 2 and 3 in theory it will make the computer happy. Has this been tried before?. ANd save the cost of a ODB1 upgrade and should woirk on a 4-1 header AND still use a unchiped Pr3 and get the most of it.

 

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

OK, need to correct my statement, I looked real close, Yes I do have 2 on the manifold, never saw the second one, but mine actually has 3 O2 sensors. 2 on manifold one on rear end of catalytic converter. What gives with that, its not shown on any of the wiring diagrams I have. But it is wired into the harness. Anyone else that bought a half cut Sir Notice this? Can anyone explain it to me.</TD></TR></TABLE>

yeah, hte thrid sensor on the back of the cat is not a proper o2 sensor...

it comes on Xsi Integra's too

it is used by hte ecu to tell if the cat is functioning properly...

if you swaped the dash over too you would see on the RHS the top light is sorta like a picture of a heating element - hte that si the cat converter warning lamp...

in all my swaps i have never wired it and never had a problem...

HTH,

t..

 

BTW - i am runnign a JDM 4-1 header with two bungs welded on no. 3 and 4 pipes for both O2 sensors tro function properly - it is the ONLY way it works...

anyone who says you can just use one O2 with a PR3 or PW0 ecu is not correct

 

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

Heres a concept I want to ask people if they have tried, since cylinders are paired for computer the mixture should be the same in pairs, what it you put 2 O2 sensors reading one of each of the two pairs, Such as on 1 and 4 or 2 and 3 in theory it will make the computer happy. Has this been tried before?. ANd save the cost of a ODB1 upgrade and should woirk on a 4-1 header AND still use a unchiped Pr3 and get the most of it.</TD></TR></TABLE>

this is exactly right,

sorry about repeating myself here, LOL!

 

how is that???

i used my ef with two b16 swaps ran maybe like **** but ran

and the second one if u don't have a spot for it what can u do???

i am using spoon 4-1 header with j's racing test pipe???

what can i do

usually it is suppose to go in the cat or after the cat correct???
and what can happen if u run only one???

will this effect higher rpm's??
and will it produce like a fuel cut

wow this is a trip i got a pr3 mugen chipped by the way....

please explain to help out others also with this sort of swap

 

it goes before the cat , THe cat cleans up whats left after the computer does what it can.

And now I need to find 2 stainless steel O2 bungs , and someone who can weld stainless so I can do the 2 O2 sensors on by JDM 4-1, since I thought as long as you got one of the paired cylinders on each of the two O2 sensors it should work. Since Tinkerbell says he has done that and it works it is going to be far cheaper than a ODB1 conversion. Even paying a professional welder to do it.

 

guys im wondering if you guys can help me out with my o2 sensor..
ive figured out that the reason im getting bad gas milage is due to my o2 sensor..im getting about 160 a tank..i have a crx with a bone stock jdm b16a. i need to replace my o2 sensor but i dont know of what car i should get it.. also planing on changing both of them.. so do i just need 2 universal o2 sensor or one of them has to be a specific primary while the other is secondary or just get two universal o2 and just put them on and it doesnt mater which one goes in.. also should i get bosch or denso(if i can find one).. thanks guys.

 

okay if u using 1st gen b16a stuff and are a EF

then like I did go to the local autoparts or what have u

get a 90-91 civic denso, bosch, or if u can NGK O2 sensor

and it is plug in a there u go

the universal are cheaper but u got to hack or crimp the old O2 u had
and they have more of a chance to look cheessey and last way last time then the ones made for ur car

hope that helps