: Replacing O2s

12-06-05, 05:46 AM
I getting codes for both B1s1 and B2s1 sensors. Should I replace both
at the same time, is it worth it while I'm in there or just one and see if it quits. I get the b1s1 code alot more.

Can anyone verify that the GM part # is 25312203 for both sensors.


12-06-05, 05:47 AM

12-06-05, 07:07 AM
I would replace any that are bad, the self tests are fairly reliable, but there can be outside influences that might cause the codes to set. Be sure it's properly diagnosed before tossing parts at it.

Usually the part numbers are the same for both pre-cat sensors and the part numbers are the same for the post-cats, but not the same for the pre-and post. I hope you know what I mean.