Oxygen sensors are not among the maintenance items that need to be replaced regularly, so they typically are replaced only when they fail.

If your Check Engine light is constantly trying to get your attention, one possible problem could be a bad O2 sensor. If you do have a failed oxygen sensor, follow these steps to replace it.

I just want to be sure of a couple of things here:<BR><BR>1) Because my problem is sensor 1 in bank 1, I should be purchasing an O2 sensor marked "before catalytic converter," correct?<BR><BR>2) O ...