MY 2005 SUBARU LEGACY i HAD FEW CODES P0420, P0137 AND P2096 ON BANK 1. I REPLACED THE O2 SENSOR AND REPLACED THE CATALYTIC CONVERTER. BUT THE P0420 CODE STILL THERE BUT DOES NOT SAY ON WHICH CAT. I WOULD LIKE HELP ON HOW FIND OUT WHICH ONE COULD BE?