at how many miles should an o2 sensor be changed

and what are o2 sims
Thanks

They should last up to 60-100 thousand miles and sims are when u gut or remove your catts. Then u plug in the sims to fool the CPU that the catts are still there.

thanks, going to change them today, car has 105,xxx on it.

Change them when they go out.

I wouldn't change them until they started throwing codes.