Originally Posted by johnzm

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