2004 Hyundai sonata eng code PL121, a throttle position sensor, but the throttle position sensor tests out good. What else could it be?

You need to replace the accelerator pedal position sensor, this is an entire throttle pedal assembly which includes the position sensor. Common fault on both Hyundai and Kia cars. This part should be under your federal emissions warranty.

code p 0101 refers to mass air flow (MAF) sensor /volume air flow(VAF) sensor --range /performance problem===causes ---intake leak/blockage ---MAF/VAF sensor
code p 0201 refers to injector 1--circuit malfunction===causes wiring---injector---ECM
code p 0224 refers to throttle position(TP) sensor B/ accelerator pedal position (APP) sensor B--circuit malfunction===causes --wiring ---poor connections --TP/APP sensor ---ECM

P0320 =no signal detected from crankshaft position sensor during cranking, my guess is replace the CPS

P2110...Faulty Throttle Actuator Control Module
- Throttle Actuator Control Module harness is open or shorted
- Throttle Actuator Control Module circuit poor electrical connection

P2118 - Electronic Throttle Control(ETC) system is made of the components throttle body, Throttle Position Sensor(TPS)1&2 and Accelerator Position Sensor(APS) 1&2. The throttle body contains the actuator, the throttle plate and the throttle position sensor (potentiometer), which are integrated in one housing. The actuator consists of a DC motor with a two-stage gear. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. And it provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.

The code means the O2 sensor is not heating up fast enough. It has nothing to do with the heater inside the car.
The sensor and the circuit would need to be tested to find out what the problem is. The code does not mean something needs to be replaced. Only tested.

The code is telling you there is a problem with the MAP sensor which measures vacuum in the intake and outside air pressure.
The sensor needs to be tested and possibly replaced.

U uvicasion del crank shaft position sensor

The sensor is located on the left hand rear side of the block (near the bell housing). It is held in place by a 10mm bolt. It's to the right of the exhaust manifold (LH - radiator side) on the V6. Once you purchase the new sensor you'll be able to identify it on the engine. The connector to this sensor is located in the illustration.
A word to the wise... replace the O2 snsr as well.

check for vacum leak

Have dealer check the computer codes - I had same problem and it required that the accelerator module be replaced - this is "drive by wire" system - no direct hookup to the throttle body.