Oxygen sensors
 

I have a 97 GMC Sierra 5.7. I have been getting a check engine light. The parts place says it is a 02 sensor. And he told me to take them out and clean them with carb cleaner, which I did. They say there are 4 of them, but I can only see 3. Anyway what I want to know, has anybody gotten them off E-Bay. Or where is the best and cheapest place to get them. I have 1 on the left pipe 1 on right pipe and 1 before the converter. Where is the 4th one ? ? ? Thanks for any help. Oh and if they are all 4 wire, are they all they same other than the plug. Oh and after I clean then, it is good for about a week. :confused:

I don't have an answer for you, but I was wondering if maybe someone could add some information on where to get a "dummy" 02 sensor?? I want to gut my CATS but the 02 sensors will throw that dumb code.

Thanks! And sorry to pirate your thread...

First off taking them off and cleaning them with carb cleaner is a myth, does not work. Only thing to do with them is replace them. The parts store has them and I wouldnt go anywhere else to buy them simply because of warranty. You may save a few bucks my friend buying them online but only a few bucks. What was the exact code he pulled from the check engine light?

Kevin those O2 simulators are hard to find now. Everyone has been gettin the tuner's to do this... http://o2spacer.com/index.php?main_page=index&cPath=11

Troubleshooting po161 sensor 2 which ever that one is. And they say there 4 but I can only see 3. Do you know if there are 3 or 4. If there are 4 than that one is really hid well. I looked all over the place for it.

if there are 4 they will be in this config.......3 pre cat and 1 post cat