o2 sensor replacement
Hi - ('93 sable 3.8) Check engine light was coming on. The trouble code said it was the o2 sensor in bank #2. I replaced the rear sensor. At first everything was fine in that the check engine light stayed off for a long time (30 minutes). Now it's starting to come on again and for longer periods. I need to pull the codes again, but I have a couple of questions.
1. Should o2 sensors be replaced in pairs? (I've heard that, but didn't know if it is true.)
2. Is it worth trying to disconnect the battery to set the computer memory back to the beginning in order to have it
re-learn based on the new sensor?