Alternator replacement?

Hello,

First of all you need test the alternator to make sure it is providing correct amount of output.
You can simply use a voltmeter to get the voltage reading while the car is running.
You should be getting around 13.6V to 15.2V with the engine running.

Here is a helpful article of how to do that:

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

You might also have a dirty Idle Air Control valve. A dirty IAC valve can cause the car to have poor idle.

Here is an article of how to clean the IAC valve:

https://www.2carpros.com/articles/how-a-idle-air-control-valve-works

https://www.2carpros.com/articles/idle-air-control-valve-service

I have attached the IAC valve location and procedure for your reference.

Please let me know of any questions.

Thank you.