O2sims and im throwing a code....

I have rear o2sims in and they work great, but today i threw a p0138 code. O2sims going bad??

very possible. do you have a scanner to see if it is moving the mV around?

Or swap them from side to side and see if the code changes to the other bank.

I cleared the code and it hasent come back sense..might of been a glitch with the sim or something.. Guess i wont worry about it till it happens again (if it happens again) *KNOCK ON WOOD*