How many O2 Sensors?
#1
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Can someone tell me how many O2 sensors I have to replace and where they are???
#2
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Been covered before and I have posted this image depicting the oxygen sensor locations in a few different posts:
![](https://blazerforum.com/forum/attachments/2nd-generation-s-series-1995-2005-tech-41/22650-how-many-o2-sensors-th_98_o2_sensor.gif?dateline=1411126189)
What is happening that you are considering changing the O2 sensor(s)? If you are doing a general tune up, only the B1S1 & B2S1 sensors should be considered for changing as the B1S3 (post-cat) is an emissions monitoring device only and should only be changed if a code specifically stating a problem with that sensor and all diagnostic procedures have been completed resulting in the conclusion that the sensor is in fact at fault.
![](https://blazerforum.com/forum/attachments/2nd-generation-s-series-1995-2005-tech-41/22650-how-many-o2-sensors-th_98_o2_sensor.gif?dateline=1411126189)
What is happening that you are considering changing the O2 sensor(s)? If you are doing a general tune up, only the B1S1 & B2S1 sensors should be considered for changing as the B1S3 (post-cat) is an emissions monitoring device only and should only be changed if a code specifically stating a problem with that sensor and all diagnostic procedures have been completed resulting in the conclusion that the sensor is in fact at fault.
#3
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I purchased my Blazer back 1n 2006 @ 96,000, and here I am about to hit 130,000. My LS says that I'm getting 14.4 mpg and I am about to do as complete of a tune up is possible before I start adding all the mods I want ie. AEM CAI, Gibson Exhaust, JET ECM programmer, CFM-Tech Ported Throttle Body and JBA headers.
#4
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So the O2 Sensor labled as #1 in the diagram does not need to be changed unless it codes???
#5
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ORIGINAL: cjbehrens
So the O2 Sensor labled as #1 in the diagram does not need to be changed unless it codes???
So the O2 Sensor labled as #1 in the diagram does not need to be changed unless it codes???
#6
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I wa just confirming thanks.
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s10machine
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02-10-2009 10:25 PM