suggestions on 02 sensor...

[Jspec7m88]

Acouple months ago, I had to replace my 02 sensor...and because of a very tight budget, I was forced to buy a "universal" 02. It worked fine...readings were always good..no smoking(not even cold starts). Well, now it's smoking nice big puffy ones in between go's. Just wondering if there is a certain kind that would be preferred. Thanks.

 

[jetjock]

I doubt your problem is O2 sensor related. Did you test it? Either in the car or out?

 

[Jspec7m88]

exactly how would I "test" it. when it does smoke, it's only for about 2 seconds, and that 2 seconds is A LOT of smoke. and it smells like straight GAS.

 

[Jspec7m88]

^^ after it smokes real bad for a couple seconds, then it never smokes again until i come up to a stop after driving for a while. ^^

 

[jetjock]

I'm not saying it couldn't be the sensor, it's just that in my experience 90% of O2 sensors are needlessly replaced. Why swap out such an expensive part as the stock sensor (or any sensor) without checking it? How to test it in the car? Use the procedure in the TSRM. You can also do it a couple of other ways, one of which is by introducing propane into the intake and pulling a vacuum line off while seeing if it repsonds.

Off the car? Use a propane torch and a DMM, an old and well known method used by mechanics everywhere and, if done right, will absolutely prove a sensor's health. Want to know more? The TSRM is online if you don't have one (you should) or Google is your friend. The interent is so much more than a global pornography network you know.

 

[Jspec7m88]

Internet...Porn. that's like the jr. high school days man. How the hell can you bring that up...that's wrong. Besides, Supramania is Internet...Internet is for learning...So I am trying to get answers that I dont know!

 

[jetjock]

Easy there big fella. My point was everything you need to know is either in the manual or online. Do you have the manual? If so are you able to follow it's instructions? Can you Google "testing oxygen sensors" and follow what you find there? Or did you have some other form of "learning" in mind? Something less strenuous?

Oh ok.....

To bench check the O2 sensor:

Do not ohm it. It's a waste of time and depending in what scale your meter is at you could damage it. Not likely but possible.

Hook your DMM up, one probe to the sensor's output and the other to it's case. Set the meter to DC millivolts or the 1 volt range. Use a propane torch to heat the sensor. Get it red but don't melt it. You're looking for several things:

1) An initial mv change within 20-30 seconds of first getting the thing hot.

2) An amplitude of at least 800 mv when hot

3) An amplitude of below 200 mv when the flame is removed.

4) As you play the flame across the sensor the output should drop and recover within 3 seconds. The faster the better. A new sensor will respond within one second for example. If it's sluggish you can always check it for a minimum of 8 cross counts per second when on the car as mentioned in the manual. (Use a scope or the frequency setting on your DMM if it has one or just count.).

5) Finally, keep the propane flame on the sensor for a full 2 minutes minimum. Again, be careful not to melt anything but keep it hot, cherry red hot. Be sure the output stays around 800 mv. Sometimes a sensor will work OK at first but die after a few minutes of being hot. There are good reasons why this happens but I won't bore you with how an narrow band zirconium sensor works as you can find that info plenty of places. An added benefit to all this is the propane will clean the sensor up.

Any sensor that passes these tests is good, and should not be replaced. The problem lies elsewhere. One that fails any of these test should.

 

[supra90turbo]

I know I shouldn't do this for you, but here's a few. Just to show how easy it is.
(sidenote: this took less than 38 seconds)
Taken from: http://www.google.com/search?hl=en&q=testing+oxygen+sensors


http://www.findarticles.com/p/articles/mi_qa3828/is_200307/ai_n9299385

http://www.ibmwr.org/ktech/O2-sensor-testing.shtml

 

[jetjock]

Good for you. 38 seconds? Imagine that. One article is wrong though. The test mentioned above is valid. Just shows what more than 38 seconds can do. Btw, no porn was involved in the making of this post

 

[supra90turbo]

Jet: Fixed the wrong one... all I did was just clicked on the Google links, then read a line or two and pasted....

BTW: Another amazingly informative post on your behalf, sir.

 

[jetjock]

Gracias Amigo. I don't mind helping out but I'm somewhat adverse to people who'd rather die than think. I'm working a half dozen forums tonight, everything from aircraft maintenance to precision welding to air conditioning, so perhaps I'm a bit short on patience. I'm sure Jspec is a fine fellow.

Btw, I meant one of your articles was wrong in that it claimed there is no valid test for checking sensors off the car.

 

[Jspec7m88]

Well, no hard feelings. We're all Supra owners one way or another. It's been a long day for me as well so I doubt I'm all there in the head anyways. Thanks for the info anyways.

 

[Jspec7m88]

Also, just thought i'd say that I've had a lot of things going on lately trying to find that new motor and dealing w/ RK right now:aigo: so I lately I've seemed to have lost my patience and just post up a thread that is currently on my mind...which sometimes leads to some rather stupid or "unclear" posts. I get frusterated and I've always been able to depend on SM so...that leads me to this. I am sorry. Forgive me!:hs:

 

[jetjock]

Hey, stop tryin' to make me feel bad....cuz it's workin' . Ask if you need anything else and I'll help out best I know how.