o2 Sensor 'trick'

[b18c1-ek]

Is this trick primarily for the sake of eliminating the pesky CEL, or is it to restore lost performance due to that code? In other words, am I losing any power due to a disconnected 2nd o2 sensor?

Thanks

[Holden]

Reading this thread makes me want to clarify something:

Cutting the secondary O2 sensor's signal wire and splicing in a resistor will end up telling the ECU the O2 content of the atmosphere, modified by whatever the resistor does. This could be very far out of line with what the primary O2 sensor tells the ECU and could trigger the CEL.

Doing what JRCivic says (disconnecting the secondary O2 sensor and feeding the ECU the primary O2 sensor's signal modified by the resistor instead) will better "fool" the ECU. The signals it gets for the primary and secondary O2 sensors will "make sense" together.

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Greg Holden
96 GSR, JSRC, I/H/E, yada yada yada...
My JRSC Install Site

[Holden]

For future reference, can anyone tell me which wire on the ECU is from the secondary O2 sensor on a 96 GSR?

Thanks,

Greg

[This message has been edited by Holden (edited July 18, 2000).]

[JRSCGSR]

Heh Greg, i dont know if this helps but on my 97 gsr, the 2nd o2 sensor signal is below the signal wire for the first o2 sensor signal. This is on the smallest connector at the ecu. I don't know if this is the same or different.

Jon

[Holden]

Thanks man. That should be correct unless Honda changed the wiring from the pseudo-OBD-II 96 ECU to the legal OBD-II ECU's used in late 96 and on.

I got an early (3/96 purchase date) GSR and Honda got fined up the wazzoo for the ECU in them! Fat chance I'll go in for that recall!

Greg

[b18c1-ek]

Just tried the o2 sensor "trick" as per JRCivic, and the CEL went out for a good 50 miles, then it came back.... this was on a 99 GSR engine, utilizing test pipes. There's no fooling the OBD-II ECU.......

Any other advice is appreciated..

[nexusone]

I'm having a CE light issue also. Diagnostics say that the system is too rich and that there is an O2 sensor error. We've checked connectivity and such and everything is fine. The shop seems to think that it's a bad sensor, but I'm skeptical. Resetting the ECU makes it go away for a while, but it always comes back on after a while. The interval varies. I'm getting sick of it. Why didnt Jackson take this into consideration?

idiots.



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[silverbullet]

Okay... so I guess the way to do this correctly is to connect the secondary o2 sensor input to the primary with a 10K ohmresistor wired in?? What happens if we use a greater resistance??

[ringer]

I've seen people talk about this trick before but I thought they used a 10 ohm resistor...not 10k. JRCivic, is it really 10k or did you type that wrong? I wouldn't know what is correct...just trying to help.

[JRCivic]

10K ohm is correct... I tried the 10 ohm and the CE light came on right away.

As for how to wire this, you must FIRST decide how many O2 sensors will be installed in your exhaust tubing. If only ONE will be used, cut the secondary O2 signal wire at the ECU, connect the 10K resistor to the ECU side of the wire, and connect the other end of the resistor to the primary O2 signal wire... this modifies the primary signal to the ECU at the secondary location.

If you are going to run TWO O2 sensors with a STRAIGHT PIPE or gutted cat, simply cut the secondary O2 signal wire in half (near the ECU) and splice in the 10K resistor in between both wire ends.


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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph