Question

Can the codes P0420 and P0430 be caused by a bad 02 sensor on my 2004 Ford F150 5.4L?

Answer 1

No, the O2 sensor just readers the oxgyen levels. Using cheap gasoline (low octane 87) can cause the catalyst converter to go bad. Using 91 octane or higher helps in the long run, were you dont spends thousands on replacing the catalyst converters, so if you get new cats dont use low octane gas and cheap brand gas stations, use Chrevon, Shell or Mobil