Cleaning oxygen sensor

[junglejuice]

Hi guys what is the best method of cleaning your oxygen sensor and is there a way to test it. I have a workshop manual for a Nissan Skyline that I had years ago and it gave you the correct signal range that it should output so you caould test it, does anybody have this sort of info for the Xj?
Cheers, Junglejuice....

[hillsjeep]

I just soaked mine it petrol for a couple of hours then cleaned it with a rag. The only test I did was make sure the error code didn't come back.

[fisher]

I used a toothbrush and some (HEAPS) of WD-40, that seemed to work, each time i sprayed it more black/brown crap came out of it. I ended up just replacing them though, i had done 128,000 on them, including about 20k without a (working) cat (now replaced).

[Gojeep]

I just replace them at 135,000, I think the manual asks for, as they get slower to react with age, regardless if they are clean or not, a new one will still out perform and clean old one.

[Rodgebone]

the only real way to test them is to watch them on a scope (in my case i use special software on my laptop connected to the pcm) and ensure they are achieving proper voltage variances (usually 0-1v with 0 being lean and 1 full rich) and also that the switching rate is lightning quick (very important) as this will usually descrease with age (as gojeep sez). a good pre cat o2 will switch very quickly and produce a tall/sharp sine wave signal from around .2 to .8 volts. the downstream o2 will switch much slower and hang around .4 - .6 volts (the sine wave will be much more relaxed and smoother). in a perfect world the two signals will be pretty much in sync. u must watch it on a scope as a volt meter will not be able to keep up. there are ways to test the heater circuit with an ohm meter but you must know which type of o2 u have as many units can be permanently damaged doing this test (dont ask me which ones u can test this way as its an inconclusive/pointless test anyways). ive also seen a difference between cleaned units and new units where the full range of signal is not achieved (let alone sluggish switching rates). cleaning might be enough to extinguish a check engine light for a time but that doesnt mean the o2 is working to its full capacity. lots of o2s which are starting to become sluggish will NOT set a check engine light. mostly the cel is a result of VERY SLOW switching rates or a dead unit. as for cleaning, dunno how you can actually get the bulb inside the protective shield thoroughly clean without touching it (as its physically impossible). spoze soaking can help but i doubt you will get it clean enuf to do its job. $75 for a new one from Inject A Carb (or less from the states) will net you bigger savings in fuel economy in the long run than cleaning. you will also gain a little hp in most cases with new stuff. for most xjs 120K is the usual lifespan athough ive seen them go much, much sooner (as little as 65K).

[Gojeep]

Thanks for all the extra insight Rodger.

[junglejuice]

I knew that someone would know this sort of info, I would have thought that the workshop manual would have this sort of info.
How much is a new o2 sensor for a 95 model roughly??????