2005 Town Car cold start idle issues

Over the last 30 days or so my 2005 Town car has been acting up when I start it when shes cold. She would normally rev at a higher rpm when cold and then idle down when she warmed up.
I have checked the throttle plate, replaced the throttle position sensor and checked for vacuum leaks. Is there a specific sensor that I should change out in my process of elimination?

Thanks for any and all input.

You should not be changing anything if you don't have service engine light on, you will be burning your cash without a real cause. Make sure your service engine light is operational and it comes on when u first open the switch if it not operational you could have codes sitting while you are totally strange to them , if the light is operational a tune up should do the trick.

Yeah, there's no question that I probably need a tune up but will new plugs solve this problem?

Yep also a fuel filter change, air filter change and plugs. But make sure you have no codes stored. Good luck bud.

If you have a throttle cable, you may want to check the idle control motor. They get clogged up with carbon and get stuck or burn up.