does anybody have a wire digram for a 99 si ecu...i'm trying to find out where the secondary o2 pins go

 

anbody have this....i know there has to be someone out there who did a obd2 swap

 

http://www.we-todd-did-racing....DE%3D

In connector A, you will notice pins 8 & 23 those are the signals for the secondary sensor. If you picture comes up small you can enlarge it.

 

I've been wondering the same thing. Two months ago my friend and I swaped a 00' B16A2 in his 00' Cx HB, and we didn't connect the second o2 sensor, becasue we didn't know where the pins were. Anyway he been driving the car like that and it seems to run strong, but looks like it's running really rich, and the check engine light would stay on. He doesn't have anything connected to the ECU (like a S-AFC) all stock. Does anyone know what would happen if we connected the second o2 sensor. Obviously the check engine light would turn off, but would it correct the car running rich... Just wondering if it's worth getting a second o2 bung welded in... We were olso thinking of doing an OBD1 conversion, and using a B16A3 ECU from a 94 Del Sol Vtec... Thanks.

 

i would think it would make it stop running rich i'm not 100%......in my 92 obd1 swap i was running with no o2 when i put one in the car ran much better

 

thanks for the pic that help me out alot

 

The secondary O2 being left out should not cause you to run rich, that is usually typical of a problem with the primary O2. The 2nd one measures the performance of the converter. Also if you have no converter in there it won't do any good to just install a bung somewhere, the sensor will not provide correct readings so the light will stay on anyways.

Make sure you run the codes off the service jumper so you know exactly what's going on with the CELs...

 

i'm not really that good with this stuff i have somone helping me out.....8 & 23 are the signals what are the other 2 wire ground

 

I think it would help too... But the car is currently running on the 1st o2 sensor (the one that plugs into the bottom of the header), so the ecu is getting an o2 reading. I'm just wondering if the second o2 sensor (the one that plugs into the cat) does anything important, or if it's just an emission thing?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HYBRIDHATCH92 &raquo;</TD></TR><TR><TD CLASS="quote">thanks for the pic that help me out alot</TD></TR></TABLE>

Those diagrams are awesome, I've used it so much. They have them for both OBD2 pinouts, OBD1, and I think OBD0 too. Crazy mad props to the genius who made those!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JRSCB16ARipster &raquo;</TD></TR><TR><TD CLASS="quote">I think it would help too... But the car is currently running on the 1st o2 sensor (the one that plugs into the bottom of the header), so the ecu is getting an o2 reading. I'm just wondering if the second o2 sensor (the one that plugs into the cat) does anything important, or if it's just an emission thing?</TD></TR></TABLE>
See the post above yours...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HYBRIDHATCH92 &raquo;</TD></TR><TR><TD CLASS="quote">i'm not really that good with this stuff i have somone helping me out.....8 & 23 are the signals what are the other 2 wire ground</TD></TR></TABLE>

You can trace the grounds in your old DX or CX harness, I think they go to one of those big connector blocks under the intake manifold. Since they are ground wires you can just find a grounding location with some other wires behind your dash and put them there.

 

Thanks... That's what I was wondering... Do you know if both o2 sensors are the same? Maybe we have something wrong with the first o2 sensor, and if there the same, we could just swap them, and see how it runs...

 

is the a site that has all the pins.....do you know what i do with the other 2 wirers off the o2.....like i said i'm not that good with this kinda thing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JRSCB16ARipster &raquo;</TD></TR><TR><TD CLASS="quote">Thanks... That's what I was wondering... Do you know if both o2 sensors are the same? Maybe we have something wrong with the first o2 sensor, and if there the same, we could just swap them, and see how it runs...</TD></TR></TABLE>
Actually I think they work the same way, the wire colors are the same and all...I'd try it and see, can't hurt!
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HYBRIDHATCH92 &raquo;</TD></TR><TR><TD CLASS="quote">is the a site that has all the pins.....do you know what i do with the other 2 wirers off the o2.....like i said i'm not that good with this kinda thing</TD></TR></TABLE>
someone has collected them all together in a thread in another forum board, but I just saved the links to the OBD2 pages in my browser's favorites folder...

OK, besides the ground wires which you now know what to do with those, you need to pull the secondary O2 plug (without cutting any wiring!) out of the harness all the way back the the ECU connectors. Find the pins 8 & 23, remove the pins from the Y7 harness and put them in the same pin location in the Si harness. You will probably have to remove whatever wires are in the 8 & 23 slots of the Si harness. It's best to avoid cutting & splicing with O2 sensor wiring since that can alter the signal voltage that gets to the ecu and give false readings...

 

Thanks for the info!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JRSCB16ARipster &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the info! </TD></TR></TABLE>
But of course!

 

thanks for all the info...i hope this works

 

I hope so too, I'd hate to have blathered on & on for no reason!!!

 

one more just in case.
http://www.clubsi.com/harness.shtml

 

thanks that will help also....the more info the better