More then likely this is an issue with idle air control valve. This controls the amount of air that comes in to set the idle speed during deceleration and at idle.
You have what is called a stepper motor so basically the PCM remembers how many "steps" it took to achieve a specific engine speed and it continues to set it at this point but when the valve wears out it may be in that position but the air is restricted or wide open allowing in the wrong amount of air.
If it were me, I would replace this and go from there. Some can be cleaned but it is best to replace yours due to it being a stepper motor.
https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac
Below is the process from the manual to replace this. Let me know what happens. Thanks
Images (Click to enlarge)
Mar 24, 2021 at 4:15 PM
