Can someone tell me if these codes mean I need to change the catalytic converter?

[DavidBGenesis]

So there's this 2010 Genesis Coupe 3.8 has about 108K miles on the ODO, I want to buy but it has the following codes (get ready because its a lot):

IMPORTANT NOTE: The car has an aftermarket exhaust. I don't know if it was straight piped though it doesn't sound too loud.

NON-MIL (What does NON-MIL mean?):
P0160 Oxygen Sensor Circuit No Activity Detected Bank 2 Sensor 2
P2273 Oxygen Sensor Signal Stuck Rich Bank 2 Sensor 2
P0158 Oxygen Sensor Circuit High Voltage Bank 2 Sensor 2
P0057 Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2

CONFIRMED:
P0160 Oxygen Sensor Circuit No Activity Detected Bank 2 Sensor 2
P2273 Oxygen Sensor Signal Stuck Rich Bank 2 Sensor 2
P0158 Oxygen Sensor Circuit High Voltage Bank 2 Sensor 2
P0057 Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2

PENDING:
P0160 Oxygen Sensor Circuit No Activity Detected Bank 2 Sensor 2
P2273 Oxygen Sensor Signal Stuck Rich Bank 2 Sensor 2
P0158 Oxygen Sensor Circuit High Voltage Bank 2 Sensor 2
P0057 Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2

PERMANENT:
P0160 Oxygen Sensor Circuit No Activity Detected Bank 2 Sensor 2
P2273 Oxygen Sensor Signal Stuck Rich Bank 2 Sensor 2
P0158 Oxygen Sensor Circuit High Voltage Bank 2 Sensor 2
P0057 Heated Oxygen Sensor Heater Control Circuit Low Bank 2 Sensor 2

So same four codes but it goes from NON-MIL, to confirmed, to pending, to permanent.

Guy selling the car told me he took it to a shop said that it needed catalytic converter, I'd like to know if the codes it shows are because of it does need one, I don't wanna buy a catalytic converter and have it turn out to be something else. Yes, I do know catalytic converter are a bit expensive but buying one is within my budget and the guy said he lower the price on the car. Could it also be that the sensors are bad? Also does anyone know if the codes point out whether it's the right or left catalytic converter?

 

[emebarak]

this is an old thread, hoping you may have solved the issue, but I think you have a oil valve intake p/n24355-3c200 blown up. and this one is impacting the other components downstream in the system. share your solution..