Can O2 sensors be cleaned?

[MagikDraggin]

I had a situation awhile back where the gasket for the TB was allowing coolant into intake manifold.

I've heard (read) that this is death for the 02 sensors and will dramatically screw up the A/F ratio.

First of all, is this true about the coolant messing with the 02 sensors, and if so, can they be cleaned, and if so. how?

Final question, when cleaned (or replaced) how can I determine if there is any difference in the A/F ratio short of doing a dyno run with a wide-band 02 sensor?

 

[KOPBET]

I don't think so and as cheap as they are I wouldn't want to try. If you have reason to suspect them then I'd replace them.

If the coolant was "death" to your O2 sensors then I would expect you would be getting all sorts of DTC codes and a check engine indication. Not to mention poor economy.

 

[Vettefan87]

Im not sure on your car but on my 87 the O2 one i have is like 15 bucks or so if that.

 

[MagikDraggin]

I don't think so and as cheap as they are I wouldn't want to try. If you have reason to suspect them then I'd replace them.

If the coolant was "death" to your O2 sensors then I would expect you would be getting all sorts of DTC codes and a check engine indication. Not to mention poor economy.

Yeah, I suppose you're right.....and I'm not getting any codes. Ok, I'll go and change them out anyways, just for good measure.

Thanks

 

[KOPBET]

Yeah, I suppose you're right.....and I'm not getting any codes. Ok, I'll go and change them out anyways, just for good measure.

Thanks

If you do, stick with the front two. No reason to rush into changing the rears behind the cats without a DTC code present.

 

[hAZcAT]

I am about to replace mine too are all three the same?

 

[KOPBET]

I am about to replace mine too are all three the same?

I believe so. They are on the '96.

 

[SSTibet]

Replaced O2 Sensors Last Weekend

Folks,

I replaced all of the O2 sensors couple days ago. There are 3 off these in the car; one in the driver side (before the catalytic convertor) and two in the passanger side (one before and one after the converter).

All 3 sensors are the same part number and I bought AC Delco products from the spares shop. I am also 99% sure that the sensors can not be cleaned and reused as they are sealed units. Another fact is that they should be replaced every couple years or so (I read this at CAC). I have also read in CAC that the signal emitted by the O2 sensor on the passanger side, after the cat, does not effect system operation. However the O2 sensors in 96 models are 4 each (2 before and 2 after the cats) and the ones after the cats are measuring whether the cats are operating properly; therefore these are important.

O2 sensors directly influence the Air / Fuel mixture (ideal value is 14.7 air :1 fuel) as they measure the amount of oxygen in the exhaust gas and emit a signal to the PCM, which is inversly proportional with the oxygen content of the exhaust gar (between 0.1 Volts for rich and 0.9 Volts for lean exhaust). The PCm receives this signal and adjusts "open time" of the injectors; i.e. how much fuel is to be sprayed to get the ideal mixture. A properly working O2 sensor has to generate a signal changing between 0.1 Volts and 0.9 Volts similar to a sine wave.

If the O2 sensors do not work properly and emit a signal between 0.35 Volts to 0.55 Volts consistantly, the PCM will default to some other settings and will keep injector open times according to those. As a matter of fact most of the time the driver does not feel the difference between the properly operating system and PCM defaults... I am guessing fuel economy gets somewhat worse and the CES light comes on the display as a result of bad O2 sensors.

Hope this helps.