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Swapping to Wideband O2 Sensor

CorneliusRox

NAXJA Forum User
Location
North of MSP
If I were to buy an AEM Wideband O2 sensor, it's got the sensor, a gauge for the dash, but then also a 5V output. Could I wire this up to output the voltage to the PCM in place of the stock one? Or would the range be off?

My understanding is the stock one gets power and ground for heating, then a common sensor ground, and a power return back to the PCM that's between 1V and 5V.
 
No. The o2 generates its own 0-1v signal. Chrysler had a biased 5v signal on the sensor solely to check the sensor. Sometimes when they go bad you will see 4v or something from the o2.
 
No. The o2 generates its own 0-1v signal. Chrysler had a biased 5v signal on the sensor solely to check the sensor. Sometimes when they go bad you will see 4v or something from the o2.

That makes sense.
Alternatively, has anyone stumbled across a little controller that could be placed in line, so it can convert that signal down to the 0-1V signal? I can weld on another bung to the exhaust, I just feel like it's kind of a waste at that point.
 
If you're familiar with Arduino/RaspberryPi hobby boards, you could down convert the signal, but honestly, that would be more work than welding another bung and cost probably the same in materials as an O2 sensor and bung.
 
If you're familiar with Arduino/RaspberryPi hobby boards, you could down convert the signal, but honestly, that would be more work than welding another bung and cost probably the same in materials as an O2 sensor and bung.

Yeah, you're right. I just did some digging too. I was looking into using a 4 Ohm and 1 Ohm resistor to made a voltage divider to scale it from 0-5V down to 0-1V, but then I thought I should make sure they output similar to each other, just with a scaling factor. That's not the case (see below).

techfjowbo2.gif


So my scaling idea won't work.
I did notice that some AFR gauges have a 'narrowband emulator' built in though. I think I'll just have to purchase one with. Basically it does exactly what i'm wanted, but it's far more accurate than the OEM narrowband O2 sensors, so it should be a (likely non-noticeable) fueling improvement.
 
Sounds like a lot of work to keep from welding a $5 bung in an exhaust pipe.
 
My AFR gauge is located inside and runs all the time. I welded a bung in the pipe for the WEGO sensor.
 
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