i have a 0bd0 jdm b16a swap in my 91 civic si right now i only have one 02 sensor wired to plug c16. i was told to use one 02 sensor and wire it to c16 and also c8, if i do this will the car run better i'm getting code 2 from my pr3 ecu and when i take off 1-3 it feels weak but ones it hits 3 rpm you feel a little kick in. do u think by me only have one 02 sensor that will happen

 

no...you can not..

 

may i ask y can't i do that and what can i do to clear code 2 on my ecu

 

Yes you can use one O2 sensor as the signal for both sensors however the car isn't going to run correctly. I did this to finish my swap and car didn't run quite right. I wired up two O2 sensors and it ran fine after that. IMO just run two O2 sensors or have the ecu chipped to remove the secondary O2.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91civic &raquo;</TD></TR><TR><TD CLASS="quote">Yes you can use one O2 sensor as the signal for both sensors however the car isn't going to run correctly. I did this to finish my swap and car didn't run quite right. I wired up two O2 sensors and it ran fine after that. IMO just run two O2 sensors or have the ecu chipped to remove the secondary O2.</TD></TR></TABLE>

 

I've run my car like that for 3 years, worked fine. O2 is disabled now, running off tuned maps, and won't go back.

 

what did the car do when u tryed to use only one 02 senser how can i get code to go away the only way is to get it chipped and tell them to disable the second 02 sensor

 

this comes up .... id say about once a week, which means you didnt search.

it does different things for diff people.

search on this crx section for "bogging" with archive checked and youll find lots of people who try to cheat and only run one 2 on a stock pre obd ecu.

you can chip the ecu to remove the secondary o2, or just pay 10 bucks to have them welded in the correct spot, and not worry about it ever again....

its certainly not going to give you any advantage whatsoever to run one, and for about 75% of people who do it, it ***** with the cars powerband.

so, in closing, you could do it the right way, or cross your fingers, and frankly, i think the people who say "it was fine" were still having less power then they could have... but they either didnt notice, dont care, or were just lucky.

but thats my opinion, not fact.

what is a fact is the tons of people on here who learned why you shoudlnt do it. theres a reason why they are so close to the block, because the single wire o2's DO NOT have a heating element during cold start warmups. and there are 2, on reads cylinders 1/3 the other does 2/4.

there used to be a b16a swap guide that told people it was ok to do it, thankfully its not up anymore.

its your car man, you can do what you want, but you shouldnt be saying "how can i make the code go away", you should be saying "how can i get the ecu the information it needs to run correctly."

welding bungs costs almost nothing, and you wouldnt have to worry about it... and if you didnt want to get the lower obd1 hole plugged bc money is tight then you could leave the 4 wire o2 sensor in there unhooked, so you dont have an exhaust leak....

 

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

Despite what I said and my probable luck, everything doublethink said is 100% correct.

 

Especially with a stock exhaust manifold you cannot run one wire for an obd0 b16a1 with good efficiency, without a modified ecu. People with stock manifolds and pw0's/pr3's that claim they run fine with one wire spliced to both ecu pins would be surprised to find they are either rich or lean when they hook a wideband unit up and watched the numbers.

The reason for this is that each oxygen sensor monitors a pair of cylinders in the 0bd0 b16 engine. If you hook up one feed to both cylinders you are blinding the control unit to two cylinders. Its a game of chance that the other cylinders will be running at the same output during closed loop. The cylinders are split in two pairs because it gives less margin for error. If only one injector was stuck open, rather then lean out all 3 cylinders incorrectly, you will only lean out 1.

Hooking up both o2's but pinning them wrong on the ecu will make a continous lean cylinder pair and a rich pair. This is because in closed loop the ecu leans one pair and richens another pair at the same time. The ecu first adjusts, and then looks for its results off the o2's. When it sees the result of the other cylinder pair that is being run the opposite direction, it will continue leaning and richening the wrong cylinders.


Modified by Profiles of Victory at 9:30 PM 11/9/2005

 

ok i do have a greddy header on my swap right now and it only has one bung and its at the end of the header down pipe is that on ok and where should i get the to weld the other bung i'm just going to pay the money and get it done right thanks for all the help guys

 

bump

 

Well if its a 4 into 1 you never will really be able to use the greddy correctly with the stock o2 process. I guess I would use the o2 bung currently on it for a wideband o2 sensor setup possibly in the future. In the meantime, plug it and weld one bung into runner 1 and one into runner 3 or you could do 4/3 or 4/2 or 1,3 or 1/2... you get the point, just make sure both firing orders are covered. I forget if cylinders 1 and 4 are considered the primary o2 on the ecu pinout charts. You will have to look it up.