Code P2098, still overheating after replacing the coolant temperature sensor and thermostat?

The p2098 code if for the exhaust system too lean so this is a separate problem you will need to make a new question for. When the engine is overheating does the radiator cooling fan come on? It is common for the fan motors to go out, with the ignition key out of the car try to spin the fan by hand to see if it rotates smoothly if not the fan motor is bad.

Here is a generic guide to help walk you the steps and instructions for your car in the images below:

https://www.2carpros.com/articles/replace-electric-fan-motor

This guide can help as well:

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Check out the images (below). Please let us know what you find. We are interested to see what it is.

When you turn the air conditioner on do you hear the radiator fan turn on or when the engine is overheating?

I think you have found the problem. First let's check the fuse # 34 and fuse J19 in the under-hood fuse panel.

here is a guide that can help, check for power at the fuses as well:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If the fuses are okay, there is a dark blue/dark green wire that goes to the cooling fan resistor behind the radiator that needs to be checked for power while the A/C is on.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is the cooling fan wiring diagram so you can see how the system works. You can try to jump the cooling fan to power to test the fan motor as well. Check out the images (below). Please let us know what you find.

Yep, the relay you swapped may be bad and is now affecting another circuit or this sounds like the famous TIPM is out which is common. Here is how to replace it which is easy because the TIPM self learns. Here is how you can change it out.

That sounds like the TIPM is deteriorating quickly, I would try replacing the unit to see if that fixes the problem.