VX o2 sensor readings

[thewizard182]

What is everyone getting for their o2 sensor readings?

This is the best thread i've found so far on vx o2 sensor readings, but it is assuming a lean burn capable ecu.
http://www.gassavers.org/showthread.php?t=2427

My car is a 92 california without the lean burn, although it does have a 5-wire o2 sensor.

My voltage readings are:

Until it warms up it's completely random, anywhere from -1.9 to +1.9
After it's warm it idles at +0.2 to +0.4
Under normal acceleration it goes from -0.4 to +0.7
When i accelerate and then let off the gas it goes to +1.9
Under hard acceleration it goes to -1.9
At 2k rpm and 60mph it goes between 0 and -0.4
If i let off the gas to the point where i'm losing speed it gets into the 0 to +.02 range

It's never very smooth of a reading, the only thing i can predict is the idle voltage, everything else jumps around alot.

It will go from 0.2 to -0.4 to 0.4 to -0.6 with each refresh of my meter, with as constant of a throttle as i can give it.

Does this seem right? I should be in the positive range at highway speed right? Remember, I have a california ECU.

[thewizard182]

Well i've got a federal ecu on the way, so i'll post up what the different o2 readings are when the fed ecu goes in.

I'd still like to know what everyone else is getting, cali or fed.

[GasSavers_TomO]

It's hard to tell what "normal" readings are for the cali version of the ECU especially when it has the 5 wire LAF in it. I am under the assumption that the readings should be very near to that of the Federal version since the readings are dependent on the sensor and not always the ECU.

The biggest issue that I see is the fact that each LAF sensor has a calibration resistor in it that the ECU uses to gauge the sensor readings it receives from the LAF sensor. This may account for slight variations in the readings you see when you compare them to the others on this board. Other considerations would be elevation and temperature at the time of the readings among all the people that have posted their readings.

I am planning on making some nice connections to my ECU this spring in order to be able to track my LAF readings. I will be able to report my findings then.

[thewizard182]

Swapped in the federal ECU.
My readings are now...
idles at +0.2 to +0.4
Under normal acceleration it goes from -0.4 to +0.5
Under hard acceleration it goes to -1.9
At 2k rpm and 60mph it goes to +1.2
If i let off the gas to the point where i'm losing speed +0.7 to +1.0

-0.4 with the CA and now +1.2 with the FED at cruising speed looks like i'm running much leaner now. I get a studder sometimes, which i'm guessing is lean burn kicking on and off. It feels almost like an automatic shifting.

It is also a much smoother reading now, it doesn't jump around and i know what reading to expect.

[GasSavers_TomO]

I personally thank you ever so much for this post. This is the kind of information that we need to purvey to the CA emissions people that want to convert to Fed emissions.

It does look like the A00/A01 (Fed) ECU is running the vehicle leaner now. And yes, the stumble that you feel is the crossover between lean/normal/rich driving.

Thank you, thank you, thank you!

[cmlamb2vx]

I've have yet to connect my DMM to the D14 and D16 pins to get the reference voltage readings, but using the just the one pin and body ground I am getting these results:

start up cold: 0.7v
30-45 sec: fluctuates up quickly to around 1.5v to 2.2v
idle: 2.9v
60 cruising speed: 3.4-3.5v
mild acceleration: 2.2-2.4v
releasing throttle after acceleration: jumps to 3.8 or 3.9v then drops down to around 1.8-2.2v then back to 2.9 to 3.1v

Does this look normal?

[thewizard182]

Just wanted to add that my best tank with the california ecu was 43 mpg, my average was 38, my first tank on the federal ecu was 49 mpg. I got about a 10 mpg increase. My old ecu may have been bad? I haven't heard of others getting that kind of an increase. Either way my car likes the federal one alot better.
Here's the link to my mpg problems thread if anyone wants it: http://www.gassavers.org/showthread.php?t=6072

[thewizard182]

Originally Posted by cmlamb2vx

I've have yet to connect my DMM to the D14 and D16 pins to get the reference voltage readings, but using the just the one pin and body ground I am getting these results:

start up cold: 0.7v
30-45 sec: fluctuates up quickly to around 1.5v to 2.2v
idle: 2.9v
60 cruising speed: 3.4-3.5v
mild acceleration: 2.2-2.4v
releasing throttle after acceleration: jumps to 3.8 or 3.9v then drops down to around 1.8-2.2v then back to 2.9 to 3.1v

Does this look normal?

If you hook it up to d14 and d16 it's easy to tell when you are rich or lean, negative is rich and positive numbers are lean. For your method 2.7v is stoic, lower is rich and higher is lean. You go slightly rich under acceleration and lean when cruising. Your numbers seem to be in the normal range.

[GasSavers_TomO]

Originally Posted by thewizard182

If you hook it up to d14 and d16 it's easy to tell when you are rich or lean, negative is rich and positive numbers are lean. For your method 2.7v is stoic, lower is rich and higher is lean. You go slightly rich under acceleration and lean when cruising. Your numbers seem to be in the normal range.

I concur...