Cleaning of oxygen sensors?

[Silver Bullet]

Is there any proven benefit from doing this, and what's the best way if so?

 

[wood_e]

....why?

 

[masho95]

....why?

I think this was the question he was asking...

AFIK I don't believe cleaning them is going to help anything. As long as they are functioning properly then they are fine and leave them alone. Cleaning them isn't going to effect whether they are function properly or not.

 

[Silver Bullet]

Basically... I was wondering if regular cleaning and removal of carbon would extend the life of the sensor, and possibly improve performance if they are dirty.

 

[olympic]

I'm guessing that you would cause more bad(damage) than good by cleaning them. It's a very sensetive part, like a MAF. They are self cleaning so if they are getting fouled on a regular basis then the problem lies in the engine.

 

[rangerj]

Olympic said it all. Like any other electronic part that operates in an extreme environment it will deteriorate and break down over a time period. The recommended replacement interval is 60K, but they commonly last up to 100K. I use 75K as a maximum.

If you have the ability to monitor the O2 sensor in "real time" you can change the sensor when it starts to "switch" slower than it should. It should switch from rich to lean regularly and rapidly as the exaust flows past it. If it is not switching, or switching slowly, it should be replaced.

The O2 sensors provide the information to the ECU about the fuel mixture. They are intended to keep the fuel mixture at the mixture ratio of 14.7 to 1, the optimum for power and efficiency. Given the cost of fuel, it is wise to replace the O2 sensors if their operation is in doubt. The operation is dependent upon the electronic integrity, not on how clean the external part of the sensor is.

As stated above, if the O2 sensor is badly caked with carbon or other deposits, then you have other problems, eg. plugs, plug wires, weak coil, vacuum leak, fuel regulation or pressure problems, etc. However, keep in mind that they usually look pretty nasty in there normal used condition. rangerj

 

[masho95]

It should switch from rich to lean regularly and rapidly as the exaust flows past it. If it is not switching, or switching slowly, it should be replaced.

Is there anyway to check how quick it's switching back and forth? IE. Does a certain wire give off different voltages while it's switching back and forth?
I currently have 103K on my car with stock O2's. Gas mileage has dropped and there is a hesitation that seems to be intermittant, but usually noticeable in 1st and 2nd gear generally around 2K-3K RPMs.

 

[Rockledge]

You can try this:

http://www.mr2.com/TEXT/O2_Sensor.html

 

[rangerj]

Excellent info Rockledge.

The ECU will code if O2 sensors are not switching. The code will indicate an "No switch detected - always lean", or "No switch detected - always rich", condition. Again, this is only an idication of a problem and not necessarily an indication of a bad sensor. The sensor could be right, that is a lean condition due, for example, to a vacuum leak, or a rich condition, for example due to a weak spark, bad plugs, or plug wires.

So, do you spend hundreds, if not thousands, of dollars on test equipment in order to determine if a $60 O-2 sensor is working properly? If you have the test equipment, or have access to it, use it. If you do not have the test equipment, and the questionable O-2 sensor has 75K or more on it, replace it.

A couple of points made in the referenced thread bear repeating.
1. DO USE RTV sealants that are O-2 sensor (and catalytic converter) SAFE
2. DO NOT use silicone spray lubricant anywhere in the engine compartment (eg throttle)
3. DO NOT use leaded gasoline
rangerj

 

[Gilbert]

I found a good tech article on Oxygen sensors available here: http://www.wellsmfgcorp.com/counterpoints/Counterpoint2_3.pdf

It is written by Wells tech support people and quite informative for those whose main job is not working in automotive mechanics. There are quite a few other articles there for those interested but judging from my previous post about it with 0 reply guess everyone here already know about it...

 

[Rockledge]

I found a good tech article on Oxygen sensors available here: http://www.wellsmfgcorp.com/counterpoints/Counterpoint2_3.pdf

It is written by Wells tech support people and quite informative for those whose main job is not working in automotive mechanics. There are quite a few other articles there for those interested but judging from my previous post about it with 0 reply guess everyone here already know about it...

I poked around the Wells stuff that you posted a link to previously. There is some interesting stuff in there. I thought the 2 piece article on fuel injectors was very good, too.

 

[rangerj]

Gilbert and Rockledge,

The learning process is never ending. It is very important to understand how the various components work, and what the indications are when they are not working, in order to make a diagnosis and repair to these computer controlled ignition systems.

The information you both provided is very much appreciated. I hope that every forum member reads both articles on the O-2 sensors, if they have not already done so. I downloaded the articles and stuck them in a "O-2 sensor diagnostics file".
Thanks again, rangerj

 

[billyshoe]

If one was to take the ox2 sensor in hand a shake it, if it rattled toss it in the scrap bin. This is a delecate piece, basically made of glass, a backfire could break it. If dropped, would break it.

 

[Gilbert]

Gilbert and Rockledge,

The learning process is never ending. It is very important to understand how the various components work, and what the indications are when they are not working, in order to make a diagnosis and repair to these computer controlled ignition systems.

The information you both provided is very much appreciated. I hope that every forum member reads both articles on the O-2 sensors, if they have not already done so. I downloaded the articles and stuck them in a "O-2 sensor diagnostics file".
Thanks again, rangerj

I always observed that the more I knew on a specific subject, the more I realised there were aspects I was still ignorant of and quite aware that I would never stop learning. Sometimes, what I read is written in a different way and explained so well, I store the info on my computer even if it does not bring anything new to my knowledge but would allow me to explain it more concisely...