Reduced Power. TVA AND Thermostat?

Hi guys,



I have 4 codes and the usual errors (Start off assistance, reduced engine power, increased emissions and a dsc error)



2B57 - "torque limitation" related to other codes

2B59 - Coolant thermostat monitor

CDC0 - Bank 2 throttle valve actuator

5E19 - Not sure



Canadian car, under CPO. Dealership says I need to replace thermostat and program the car. I know that won't fix the throttle valve actuator issue. Any suggestions? I can replace the thermostat myself, but I'm not sure if there's an actual issue or if it's being caused by something else. Apparently in Canada the thermostat isn't covered by CPO.



Thanks in advance.