Going to attempt changing out the O2 sensors on my 2GS3 this weekend. Should I replace both sensors on the same bank? Or just changing out the faulty one is sufficient?

 

Just change out the faulty one.

If it ain't broke why fix it.

 

I agree with GSoup.. there really is no need to replace both sensors. Plus, replacing the second sensor on the same bank would do nothing for you anyway. Replacing both of the forward sensors (Bank 1 Sensor 1 and Bank 2 Sensor 1) might help, but not likely. The rear sensors (Bank 1 Sensor 2 and Bank 2 Sensor 2), are just there to confirm that the cat is working, replacing them if they arent bad wont benefit you. Just replace the bad sensor.

 

Cool. I'll just replace the faulty one. Thanks for the help.