Ok, your engine is a 4.8L V8.
DTC P0332 - Knock sensor #2(rear knock sensor) low voltage
If engine has an internal engine knock, such as rod knock, this need to be repaired first. if there is no internal engine knock, most of the time it is a faulty knock sensor. The knock sensor is located under the intake manifold.
DTC P0430 - Low efficiency in bank 2 catalytic converter
Possible causes include faulty converter, inside of converter has come apart and rattling, converter body damaged such as dents or holes, exhaust leak between exhaust manifold and converter, O2 sensors wiring resting on exhaust pipe.
Because both of these codes are referring to bank 2(right side exhaust), have converter checked first. A converter that the inside has come aprat and is knocking around in the converter shell can set the knock sensor code. If this is the case, have converter replaced, reset computer and see if code resets for knock sensor. If it does, then the intake manifold has to come off to replace it. If no code comes back, then knock sensor code was set by failed converter