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Hi guys,
Relating to the two wire type O2 sensors on the factory VX series na 3800 vehicles.
In the TunerPro RT, what actually determines the O2 Sensor Status as Ready and not Ready?
What is this actually also referring, I presume it is when it is at running temperature? If so, how does the TunerPro know the sensor temp on a 2 wire sensor?

I believe the 2 wire sensor readyness is just a timer from engine start making some assumptions about time to heat.

antus wrote:I believe the 2 wire sensor readyness is just a timer from engine start making some assumptions about time to heat.

Thanks for the feedback and thoughts.
I agree with you there as I can imagine that a countdown time method might be the only way to judge its readyness. Along with ECT maybe as well?

So I question why I am getting them Ready, Not Ready at different times while the motor is running/driving/idling. Also they are changing states not in sequence with each other? One noticeably more than the other. Well, that is what TunerPro RT is displaying.

Could this be the link in what i think is excessive amount of times that the car cycles in to Open loop mode and minimal time in closed loop mode?

What are your thoughts?

I could be wrong about the timer. It is the case on the older models. The other way it might be doing it is looking for the right amount of cross counts. Perhaps its failing or slow and the PCM can see the data coming off it is is not correct. If someone knows for sure please speak up.

When the sensor drops out of been ready check the sensor output voltage. I believe it compares voltage Vs time, if the voltsge is too low or too high it should set an CEL.

At start up I believe closed loop is governed by run time and ECT which I believe is 30 degrees C. During cold start it would monitor O2 sensor voltage output as it will chage with temperature.

Ok, from what TunerPro RT log is showing me. Not that TunerPro allows for the displaying of both O2 ready condition and O2 voltage at the same time. So I have to go by the timeline to view both different feedback at the same timeline range.
When the O2 sensors status is Ready, the O2 voltages are sill waving between the 0.750 and 0.150 mv ranges. Which is also close to but larger swing to that of the O2 sensor readings when the ECU is in open loop mode. This shows me the O2 Sensors are working?

I notice that a previous log record shows more stable Ready status of the O2 sensors. I might flash the CAL back to that point in the morning and see if the O2 sensor issue fixes. That should show me if it is a ECU tune issue or possibly failed O2 sensor issue, I think.

What is the BLM Enabled status relate to ?

They will go to the ready state if they are hot enough and output changes from a steady 0.450v they can cool off and go out back to saying not ready if the egts are cold

delcowizzid wrote:They will go to the ready state if they are hot enough and output changes from a steady 0.450v they can cool off and go out back to saying not ready if the egts are cold

With the variants in weather here in SA these past few weeks, that could be plausible they may be on the boundary of being cooled off, I guess. Though I would have thought that I would also see a temp change in the air intake temp sensor to show a variant as it would be sucking in air temp changes as well.

With the variants in weather here in SA these past few weeks, that could be plausible they may be on the boundary of being cooled off, I guess. Though I would have thought that I would also see a temp change in the air intake temp sensor to show a variant as it would be sucking in air temp changes as well.

He isn't talking weather here, he is talking about EGTs

EGTs can have many contribuing factors.

Timing / fuel mixture would be some big determining factors.

Running rich will have cooler EGTs then running leaner, retarded spark advance can cause excessively hotter EGTs
More advance would be cooler.

If you've ever run an engine at 3000rpm at 0 degrees or less of timing for and extended amount of time, it WILL get hot.

If I remember about this topic tomorrow, I'll pull up the oxygen sensor descriptors from the workshop manual for Gen 3. I know yours is a V6 but the principle on how the sensor works is the same.
Off the top of my head, when the ignition is applied, they are pulled up to a constant 450mv, when they heat up, the millivolts will start to transition away from 450mv.
At which point the ecu assumes the sensors are warm enough to start doing their job, readiness will be achieved and closed loop can commence.