Pontiac Repair: smog, catalitic converters, oldsmobile intrigue

Question
I failed CA smog on 1998 Oldsmobile Intrigue 3.8 eng.  I replace 1 bank O2 sensor for code P0420 and reset the engine soon light.  I drove it about 45 miles before etting the smog.  engine soon light never came on and I scan it will all pass code. here are my number any ideal?  Thank you for your time and help.
  RPM   %CO2   %O2   HC PPM         CO %         NO PPM      
           MAX   AVG   MEAS   MAX   AVG   MEAS   MAX   AVG   MEAS
15 MPH   1846   14.8   0   51   9   24   0.48   0.02   0.22   419   57   585
25 MPH   1789   14.1   0   35   7   20   0.46   0.03   1.39   706   50   181


Answer
Hi there Donato:

A O2 sensor is not going to fix a p0420 code. The Catalitic converter is bad. It's not doing it's job anymore. Too much "smog" is comming out of the tail pipe. If you drive this more eventually the code will come back. Just because the codes all passed their tests doesn't mean it will pass the sniffer test for the state. It could be right on the verge of good and bad and ready to turn on the service lamp and fail the tests for the state. There are a few product on the market that state they will help you pass a smog test you may want to try them. They claim to "clean the catalitic converters" I don't buy it but it's worth a shot it's cheaper then buying a new converter. Good luck :)