Autometer wideband voltage

JGDogg10

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Hey guys, I’ve done a bunch of research and can’t get a straight answer for datalogging. I have an autometer c2 wideband, sct x4, and livelink. I contacted sct and wired the red FireWire cable to the positive analog out on the gauge, and the black wire to the negative analog out from the gauge(how sct said to wire it). When I log analog 7(red wire) on my x4 or livelink the voltage when idling is around 3.4 but my wideband is reading right at 1 lambda or 14.7 afr. Autometer uses a 0-4v sensor, but the voltage it’s reading from the datalogs at 3.4v doesn’t make sense. Right? I figured the voltage should be around 2, the middle point of the capable voltage of the sensor. What’s even more weird is the voltage will spike to over 6 volts on the x4 or livelink. Is it just something that is wired wrong to the x4 since my wideband seems to be reading dead on?

And if I enter the formula to convert to afr in the sct program, it’s reading way lean compared to my actual gauge. Autometer said (v*2.5)+10 based off 10.0-20.0 range with 0-4v


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robvas

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Are you sure it's a 4v sensor and not a 5v sensor? And are you sure of the range? I would check the manual for the actual sensor you have, they aren't all the same

IF, and this is an IF...

If your sensor works on the 10:1-17:1 range for the 0-5v (assuming a 5v sensor, not a 4v)

You can do the math like so:
7/5 (1.4) * 3.4 = 0.476
10 + 0.476 = 14.7 AFR

You're adding 10 because that's the lowest the sensor can read. And the multiplication factor (1.4, is the AFR range of the sensor divided by the voltage range), so 2.5 doesn't make any sense.
 

JGDogg10

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I’ll try it out! I’d have to look if I could find the manual for it. I’ve had the gauge for like 10+ years haha

Still think it’s weird tough for it to be spiking to over 6 volts at times… right?

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JGDogg10

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Well I tried that out and it’s honestly pretty damn close! Still baffles me with the voltages, but now I just gotta convert the formula to lambda


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