Cleaning an o2 sensor with propane torch?

[brianl703]

I replaced the o2 sensor in my friend's truck because the mode $6 test results showed that it was on the verge of failing.

The new o2 sensor definitely improved the test results and the truck runs better.

The old o2 sensor had some carbon deposits on it.

I decided to take the o2 sensor and do the propane torch test with it: Connect it to a multimeter, put it in the flame, and see what the highest voltage it produces is. It got up to .8V and dropped to 0V instantly upon removal from the flame. I think this indicates a good sensor.

This also cleaned all the carbon off the sensor.

Has anyone used a propane torch to test/clean an o2 sensor? I'm wondering if this sensor will work better now. It got red-hot while it was in the flame.

 

[Rabbler]

An O2 sensor can reach min an max voltage and still fail.
It probably wasn't switching fast enough and that's why it failed.
Toss it in the trash.

 

[andyd]

Yup, similar results when I tried it on the original 280k O2 sensor. I got it red hot and got it to .9v but installed, it wouldn't change state rapidly enough.

 

[GMBoy]

Originally Posted By: Rabbler
An O2 sensor can reach min an max voltage and still fail.
It probably wasn't switching fast enough and that's why it failed.
Toss it in the trash.


X2. Plus, sometimes the heater circuits fail.

 

[JTK]

Originally Posted By: GMBoy
..Plus, sometimes the heater circuits fail.


Right, but the heater doesn't effect the sensor's functionality at all. It just won't come up to temp as fast. Plus you'll get the joy of a constant check engine light associated with the "heater circuit malfunction". Been there.

Joel

 

[Rabbler]

Actually the heater can effect sensor operation.
The heater will help maintain a minimum operating temp.
On many vehicles the exhaust temp at idle isn't hot enough for proper O2 operation.
I've had a few bad O2's that would switch fine while driving but stick at idle.
A couple would actually cause the system to richen up so much black smoke would roll out the tailpipe.

 

[mechtech2]

That propane test is useless.
Hillbilly reasoning.