CAN YOU HELP ME WITH WHAT NEEDS TO BE DONE?

P0420 - Catalyst System Efficiency Below Threshold (Bank 1) P0118 - Engine Coolant Temperature (ECT) Sensor Circuit P2181 - Coolant System Performance Looks like there is a coolant temperature sensor problem. It would probably need a new ECT sensor, I'd also replace the thermostat. The P0118 and P2181 are should be related to the same problem. The P0420 is a catalytic converter efficiency problem. First the Oxygen (O2) Sensors had to be checked. The efficiency is measured by the rear O2 sensor. If the sensors are OK, the car needs a new catalytic converter. Before a new converter I'd make sure the PCV system works correctly, the car isn't burning oil, the injectors are OK, not leaking and dumping extra fuel, etc... Zee