Help With Codes 2000 Silverado

:banghead: IM HAVING TROUBLE FINDING WHAT IS THE PROBLEM THE FIRST TWO CODES ARE PO137,PO157 THAT IS O2 SENSOR AFTER THE CAT THE OTHER CODE IS THE KNOCK SENSOR IM WANTING TO KNOW IF THE O2 SENSOR ARE BAD AND THROWING THOSE CODES WOULD IT ALSO MAKE THE PO332 CODE KNOCK SENSOR TOBE THROWN.... IM ALSO GETTING A PO463 CODE THAT IS A FUEL SENSOR LEVEL WHAT IS THAT IS THAT MY FUEL PUMP
NEEED HELPPPP THANK YOU ANY HELP SHREK 2000CHEVY