I hate check engine lights so I want to fix this problem. I put in a first gen b16 into my car about a month ago and I want to get rid of the secondary O2 code the ecu is throwing. Does anyone know how to fix this problem without chipping the ecu? Can I splice two wires into one O2 sensor and trick the ecu? Any help would be great.
i’m assuming you’re using a pr3…
if so, as i understand people have jumped the pinout from the first 02 and connected to the pin for the second, essentially using the signal from 1 o2 to feed both pins. the problem with this, is that i think it would cause resistance problems. if so, you’ll get a bad read anyway. i’m just did the swap and am having my ecu chipped…
ever thought of having a second bung and o2 added? or just chip it. honestly…
btw…i used to live in glendale. let me know if you need any help w/ your car 
jsut gotoa muffler shop and get a 2nd o2 welded in. it’s not that big of a deal…
g2teg27: Thanks alot for the offer, next time I run into trouble I’ll know who to get ahold of.
I really don’t want to make holes into my header, I’m trying to avoid that.
well trickin the ecu into thinking that 1 sensor is 2 was bad for my b16. it ran like fucking shit until i wired both correctly. i dont think you want to take that route either, just do it the right way.
Could I just ground the secondary o2 sensor for right now so that my ecu will quit throughing the code?
if you are worried aout drilling a hoel into your header. then put it right after the header. Not very ideal but it’ll work and not throw codes.
i must have the “nicest” PR3 ecu out there. Haven’t had my 2nd O2 wired in and haven’t gotten that CEL in the past year i’ve had that ecu. Its wierd, but hey im not complaining lol.
I ran only 1 for a while too and no CEL. but later on I added it in and it seemed to be a bit smoother and better gas mileage
same here, i never got a CEL but it idled funny and bogged and sputtered while holding the throttle steady at any speed. gas mileage sucked ass too. wiring both 02’s correctly is probably the best thing i’ve done to my motor :bowdown:
yea…i was going to do it but i planned on doing an obd1 conversion. since i just got done making my own conversion harness i’ll probably do it pretty soon, so i won’t bother making the 2nd O2 bung. 
Can anyone explain how to wire the o2 sensors up??? I bought a DA with a pr3 b16 and all the wiring suxs. Im trying to go back and rewire everything. And tonight when I cut the wires I didnt know how they go. So right now im throwing a code 7.
for those of you who only wired one: http://www.hondata.com/techo2problem.html
for those of you looking how to wire:
http://hondata.com/techwiringpw0.html
and a quick tip: The cream colored plug on the b18a on a pr4 ecu goes to c16. on a pr3:THE CREAM COLORED PLUG GOES TO C8. THE GREEN ONE GOES TO C16. SWITCH THEM AROUND.
let me know how ti goes 
That write up seems very similar to what im feeling. Im checking to see if the O2 sensors are wired into the right pin.
naisab18a1 -
maybe you could clear this up for me… i have an RS*R header made specifically for the obd-0 b16a, with 2 02 bungs. when i installed, i didnt pay attention to the stock piece and just took a guess on which sensor goes to which ecu pin.
so in other words, i dont know if the sensor wired to C8 is necessarily supposed to be there, it might be C16?
if i took pics of the manifold and the bung location, would somone be able to tell me which sensor is supposed to go in which bung??? i think this is why i’m running SOOO rich. i failed smog by like 5x the limit so mabye thats why…
hope that all makes sense
green: monitors cylinders 1 and 4. c16 pin on pr3/pw0 ecu.
cream: monitors cyliners 2 and 3. c8 pin on pr3/pw0 ecu.
cylinders read:
FIREWALL
4 3 2 1
FRONT OF CAR
see how there is a bung on primary #3 and #4? thats what confused me during the install, because the stock b16a manifold had them in completely different spots like where 2 primaries meet… i cant wait to get home and check, i hope they’re right 
thanks for the info and links
no problem man. I was havin the same exact problem as you, and it was freakin me out. I wanted to get it done right, but thankfully i did it corrrectly. I had to add a bung to my dc header, but the connecting flange rubs on the block, so not it makes noise… sigh… time to find the right header i guess. :run:
The article I got off that hondata link worked. Both the o2’s need to be swicthed and I can tell a diffrence.
thanxs naisab18a1
later
well, im sure someones gonna stumble onto this problem again. archivethis