O2 sensor differences & specifications

[Timothy Bucktu]

My Mum has a 2002 Honda Civic 1.6.
The pre-cat O2 sensor is complaining about the Heater circuit malfinctioning. Sure enough, it's open circuit.
Not to worry...I have a couple of spare Lambda sensors.
First was a used one from a Ford Focus. This has a good heater, but the car threw a high voltage error. Sure enough, it was peaking at around ~1.2v on the scope.
Next I tried a brand new spare that I have for my MR2. Again, heater all good...but this also threw a high voltage error...again, it was peaking at ~1.2v
So I put the old one back in, and this does indeed have a lower voltage, peaking at <1v

I always thought these sensors were fairly bog standard...the only usual differences are whether they have a heater or not.
I know some are wide band - could that be the difference here?

[stevieturbo]

Timothy Bucktu said:

My Mum has a 2002 Honda Civic 1.6.
The pre-cat O2 sensor is complaining about the Heater circuit malfinctioning. Sure enough, it's open circuit.
Not to worry...I have a couple of spare Lambda sensors.
First was a used one from a Ford Focus. This has a good heater, but the car threw a high voltage error. Sure enough, it was peaking at around ~1.2v on the scope.
Next I tried a brand new spare that I have for my MR2. Again, heater all good...but this also threw a high voltage error...again, it was peaking at ~1.2v
So I put the old one back in, and this does indeed have a lower voltage, peaking at <1v

I always thought these sensors were fairly bog standard...the only usual differences are whether they have a heater or not.
I know some are wide band - could that be the difference here?

Perhaps give a little more info ?

How many wires on your original lambda sensor ? What colours ?
What are replacements listed as ?

And exactly what are you testing and how, as peak voltage is largely meaningless. If the engine is in closed loop, you should see the voltage swing either side of stioch.
If open loop, then voltages should reflect mixture changes as engine load changes.

If the sensor is not warm enough, heater not working, this will reduce any response time for the sensor.

So what is actually happening ? Your original fault claim is only the heater circuit, so was the heater working ? Was the sensor signal offering anything ?

Not all sensors are the same, so it depends entirely what you started with, and what you tried to replace with.

Some Hondas and indeed Toyotas used specific sensors, swapping at random may not be a great idea.

[stevieturbo]

https://www.hella.com/techworld/uk/Technical/Senso...

[LordLoveLength]

You sure it should be a lambda sensor not an air fuel ratio sensor?
Different voltages and characteristics- jap cars often use them.