Should i replace my o2?

Hey guys i got a 98 gst w/t 107k miles. Should i replace my o2 sensors? what benifit would i get and should i just replace one or should i do both at the same time? Thanks for the help!

Are you sure you need them? If they are bad you could improve your gas milage slightly... But it wouldnt be worth it.. One way to know if you need them replaced is if you are blowing a lot of black smoke out your tailpipe...

I would suggest leaving them alone tho, unless they are bad..