I have a 1995 Maxima check engine light came on bad 02 sensors in front of converter, replaced sensors ,cleared computer drove 5 miles check engine light reappeared ,bad knock sensor code changed it, cleared computer.I drove short distance check engine light back on code reads bad 02 sensors I just changed.I had the car at the dealer the first time to read code and local garage second time being a 95 few places can read computer.I feel the converter maybe the cause but not sure .The car has a 143000 miles on it and is running great any other ideas why the light reappeared.

Did you install OEM oxygen sensors? Did you replace all upstream and downstream oxygen sensors?