i have been searching for quite awhile. i have an obd0 b16. i got a greddy header from an 00 Si with one o2 spot near the cat. i currently have wired both o2 wires and my air/fuel gauge to that one sensor. it seems to be running ok, but i'm sure this is not the best way. i know i can get a couple o2 bungs welded in the proper spots, or get a chipped ecu, but i'd rather not.

i am wondering if anyone has tried something else?? diodes on the wires to isolate the signal? does a chipped ecu that deletes the second o2 really work that well? any experiences would be great, thanks

 

If you stay with the OBD0 ECU You need to weld two bungs in the header up near the head on the original spot and wire the two O2 1 wire sensors. Problem solved.
If you change to OBD1, then leave the O2 bung where it is and replace it with a 4 wire O2 sensor, a OBD1or 2 Distributor and a OBD1 ECU chipped.

One O2 sensor with the original OBD0 B16 ECU is not the way to go.

 

thanks. i also have a supposed 'spoon' ecu lying around that definitely ran better before i did any mods. do you think that will work well with this one sensor?

i also have an extra bung on the cat...do you think having the second o2 sensor there will work? is location that important?

 

I think 18-36 inches from ports is sufficient to produce a proper reading for a normal O2 sensor correct? I've never seen an OBD0 ECU that needs 2 sensors.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IndySporty &raquo;</TD></TR><TR><TD CLASS="quote">I think 18-36 inches from ports is sufficient to produce a proper reading for a normal O2 sensor correct? I've never seen an OBD0 ECU that needs 2 sensors.</TD></TR></TABLE> the pr3's need 2 sensors

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IndySporty &raquo;</TD></TR><TR><TD CLASS="quote">I think 18-36 inches from ports is sufficient to produce a proper reading for a normal O2 sensor correct? I've never seen an OBD0 ECU that needs 2 sensors.</TD></TR></TABLE>

The factory places them 8 to 10 inches from the exhaust ports.
There are two OBD0 ECUs that use 2 O2 sensors, PR3 and PWO. There might be more.

The "spoon" ECU might not even look for O2 sensors. Those were racing programs and for the most part they don't care for O2 readings.

If you care about mileage, then forget the spoon ecu and install the 2 O2 sensors where they need to go and wire them correctly.

 

read!

 

The sensor needs to read the cilinder in pairs.

cil 1&4 and 2&3. So you will want to put the o2 sensor where these meet (4-2).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Maxbore.com &raquo;</TD></TR><TR><TD CLASS="quote">The "spoon" ECU might not even look for O2 sensors. Those were racing programs and for the most part they don't care for O2 readings.
</TD></TR></TABLE>

Does anyone have any more info on this? I was planning on using my mugen header on my ef8 with an obd0 Spoon ECU but if I NEED to utilize both O2 sensors, I will just have to get another header because there is NO way I am going to modify the jasma. I was thinking the same as MAXBORE... I wouldnt need them since its a race program, but I am not sure. any info is appreciated, Thanks!!!

 

thanks for the info guys...and i did read that article just now. as for the spoon ecu, i know it ignores certain things as my car had a CEL for crank position sensor (in the distributor) and the CEL went away with that spoon ecu. i'd imagine it ignores the o2 sensors as well. however, i replaced my dizzy and have been using the stock pr3.

that hondata article says 'Wiring one oxygen sensor into the two ECU pins will produce a similar problem, except the ECU will alternate between running each cylinder pair rich and lean.'

i understand what that means, but i would think it just sees the current exhaust mixture going out...why would it alternate? anyway, i wired up some diodes today to isolate the primary and secondary o2 wires for the ecu. i only drove it to the college and back, but it seems pretty decent! i will probably take a longer drive tomorrow and try that spoon ecu later.
i'll keep you guys posted, but if anyone knows more please let me know

 

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

Does anyone have any more info on this? I was planning on using my mugen header on my ef8 with an obd0 Spoon ECU but if I NEED to utilize both O2 sensors, I will just have to get another header because there is NO way I am going to modify the jasma. I was thinking the same as MAXBORE... I wouldnt need them since its a race program, but I am not sure. any info is appreciated, Thanks!!! </TD></TR></TABLE>

I had a stock PR3 ECU in my CRX waaaay back. The halmeter ( A/F gauge) would fluctuate from lean to rich as I was cruising. That's the normal way the stock ECU tried to achieve stoich a/f ratio. After I swapped the Spoon ECU, the halmeter was solid at rich during cruising. The truth is, nobody can tell by just looking at the ECU what it is going to do. A lot of the Spoon and Mugen programmed ECUs out there have been modified and no longer are 100% mugen/spoon.

 

here's an update guys:
one of the studs broke when i installed my greddy, so i decided to put my stock header on with new o2 sensors and see what it does for a baseline. i too thought the pr3 goes from lean to rich while driving, but it really doesn't. it starts rich and once it warms up it's at the high end of stoich or low end of rich...it stays in a relatively narrow range. it will go lean when letting off the throttle, but that's normal as the injectors are shut down. i drove around about 30min and it was actually quite consistent.

now before i did all that, i tried a few diodes and some various wiring using that one o2 on the greddy. at one point, it ran very similar to stock...but i believe the o2 sensors were not reading as i had the diodes pointed the other way. if they were essentially disconnected, wouldn't i get a CEL? or does it just see it the open circuit as running rich like when the engine is cold? using the diodes and one o2 i was running in a narrow range just slightly richer than the stock header. i may go back to that setup and see if mpg is affected on a whole tank of gas.

 

im positive its the original pr3/pw0 b16a program, the ecu had the seals. I just wanted to know if that spoon ecu uses both o2 sensors? many have said it uses none... not sure.