Narrowband A/F Gauge Wiring Question
I wired it up to the black wire on the bosch o2 sensor which is supposed to be "signal". (I think the stock harness it's purple) Anyhow it's wired to the signal wire.
When i start the car (cold start) the gauge will sit in the middle as I'd expect (I know these aren't accurate) and then as the car warms up it slowly drips down to the left/red/lean side and then once warm it totally disappears. I've only seen the gauge start working again when the gas is released then it pops back up in the middle.
My understanding is this signal is very narrow, from 0 to 1 volt and the gauge would show readings only during throttle or wide open throttle. Mine is not showing any lights during wide open throttle or part throttle once warm.
Is it possible the wiring isn't right or should I try the passenger side sensor? Or is it possible my car is actually lean.
I know you can't go off of these gauges but I've seen them on other cars and the pretty little light show is constantly appearing on the gauge, while mine just doesn't do anything.
I wanna see the shiny lights when I'm driving, regardless if they are useless.

PS: I'm gonna upgrade to a wideband in the not so distant future.
Last edited by Mike96z; Feb 6, 2018 at 10:38 AM.
I wired it up to the black wire on the bosch o2 sensor which is supposed to be "signal". (I think the stock harness it's purple) Anyhow it's wired to the signal wire.
When i start the car (cold start) the gauge will sit in the middle as I'd expect (I know these aren't accurate) and then as the car warms up it slowly drips down to the left/red/lean side and then once warm it totally disappears. I've only seen the gauge start working again when the gas is released then it pops back up in the middle.
My understanding is this signal is very narrow, from 0 to 1 volt and the gauge would show readings only during throttle or wide open throttle. Mine is not showing any lights during wide open throttle or part throttle once warm.
Is it possible the wiring isn't right or should I try the passenger side sensor? Or is it possible my car is actually lean.
I know you can't go off of these gauges but I've seen them on other cars and the pretty little light show is constantly appearing on the gauge, while mine just doesn't do anything.
I wanna see the shiny lights when I'm driving, regardless if they are useless.

PS: I'm gonna upgrade to a wideband in the not so distant future.
The ECM is constantly "dithering" the fuel mixture a little bit to either side of "perfect". It looks for the O2 sensor to respond accordingly ("cross counts"). Therefore an additional NB in the exh stream should indicate more or less the same thing.
Keep in mind, your gauge may have enough "averaging" or "smoothing" to take the stock variation around stoich completely out of its indication. You probably wouldn't want a gauge in your dash that constantly flickered all its lights at a rapid rate, after all.
If you hooked your ECM up to a sensor that behaves as you describe yours, it would command the mixture rich all the time, since its "eyes" (the O2) would be "seeing" lean, and it would compensate accordingly aka feedback aka closed loop... a common reason that O2s need to be replaced.
The Four Wire EGO is NOT TRASH, the NTK or Bosch units are what I have observer/tested.
The other manufactures of EGO's, I have little information.
The tests began is the 1980's when I tested the NTK UEGO in the SAME PIPE/Same Time next to their Three Wire EGO.
I added a Gray wire to the sensor body for Signal Return, a hose clamped wire connection.
I then compared the Voltage Output of the EGO to the Current Demand of the UEGO finding EXACT correlation AT AFR's from 12.65:1 - 16:1 OR Normal engine operation range.
The NGK plant president (Japan) in Irvine brought his engineers the my shop for the Dyno test after my SON and his SON Pre-witnessed the same test procedure.
They were VERY pleased with the test results ALLOWING me to buy the NEW Four Wire EGO sensor from WIXOM, the ONLY one allowed to due so. (over run production ONLY with no connector)
I then developed the PAF software/firmware to allow my ECU to use the new Four Wire Sensor AND have a AFR TABLE based on sensor OUTPUT VOLTAGE.
Thus :
Black = Signal
Gray = Signal Ground
White (two) = heated power/ground with no polarity
Sensor operating temperature range is 600F-1600F with "drift" reported OUTSIDE this range.
Lance
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I manufacture Lambda meters AND UEGO boxes used to supply current to the Nernst Cell in an UEGO.
The Lambda Meter I supply, designed, does use LEDs for a five color read of TWO each color.
The A/D uses a 0-1 voltage reference with FILTERS designed to SLOW the color change speed for an easy read.
The UEGO box I manufacture HAS a 0-1 Volt output, a 0-5 Volt output AND CAN 2.0B output.
The CAN (Bosch MS words) can be read by my GUI for an eight channel display on a Laptop/PC.
My UEGO box has E-MAP correction.
Lance
The Four Wire EGO is NOT TRASH, the NTK or Bosch units are what I have observer/tested.
The other manufactures of EGO's, I have little information.
The tests began is the 1980's when I tested the NTK UEGO in the SAME PIPE/Same Time next to their Three Wire EGO.
I added a Gray wire to the sensor body for Signal Return, a hose clamped wire connection.
I then compared the Voltage Output of the EGO to the Current Demand of the UEGO finding EXACT correlation AT AFR's from 12.65:1 - 16:1 OR Normal engine operation range.
The NGK plant president (Japan) in Irvine brought his engineers the my shop for the Dyno test after my SON and his SON Pre-witnessed the same test procedure.
They were VERY pleased with the test results ALLOWING me to buy the NEW Four Wire EGO sensor from WIXOM, the ONLY one allowed to due so. (over run production ONLY with no connector)
I then developed the PAF software/firmware to allow my ECU to use the new Four Wire Sensor AND have a AFR TABLE based on sensor OUTPUT VOLTAGE.
Thus :
Black = Signal
Gray = Signal Ground
White (two) = heated power/ground with no polarity
Sensor operating temperature range is 600F-1600F with "drift" reported OUTSIDE this range.
Lance
The Four Wire EGO is NOT TRASH, the NTK or Bosch units are what I have observer/tested.
The other manufactures of EGO's, I have little information.
The tests began is the 1980's when I tested the NTK UEGO in the SAME PIPE/Same Time next to their Three Wire EGO.
I added a Gray wire to the sensor body for Signal Return, a hose clamped wire connection.
I then compared the Voltage Output of the EGO to the Current Demand of the UEGO finding EXACT correlation AT AFR's from 12.65:1 - 16:1 OR Normal engine operation range.
The NGK plant president (Japan) in Irvine brought his engineers the my shop for the Dyno test after my SON and his SON Pre-witnessed the same test procedure.
They were VERY pleased with the test results ALLOWING me to buy the NEW Four Wire EGO sensor from WIXOM, the ONLY one allowed to due so. (over run production ONLY with no connector)
I then developed the PAF software/firmware to allow my ECU to use the new Four Wire Sensor AND have a AFR TABLE based on sensor OUTPUT VOLTAGE.
Thus :
Black = Signal
Gray = Signal Ground
White (two) = heated power/ground with no polarity
Sensor operating temperature range is 600F-1600F with "drift" reported OUTSIDE this range.
Lance
Anyhow, I think I may know what my issue is but not exactly what is causing it.
In HPTuners, my LTFT and STFT are always 0. I checked and LTFT is deff enabled, but I'm not sure why it's not showing me anything. Maybe both of my o2 sensors are bad?
Looking at the o2 graph they sensors never move much, they stay around 452-453mv.
Any thoughts?
Last edited by Mike96z; Feb 6, 2018 at 10:48 AM.
But that brings us back to why the fuel trims are just sitting at zero. One of your screenshots above shows that the "Fuel system status" is "Open Loop - Not ready". Does that change after a minute of running, or does it always say that?
Does this mean my o2 is bad? That's the one the gauge is reading from, which could explain the strange behavior. It's probably getting a signal but not sending anything back?
I'll check to see where my OL/CL temp is set.











