Issue:
when car is cold or first started for the day,
the car revs to almost 2.2k for at least five
Minutes ,before slowly idling down over 10 minutes to get to normal idle speed.

Could this be related to the air cleaner?

I have cruise control, it works fine no vac leaks.

90 tbi rs

this has been an ongoing issue since I bought the car, but if it’s real hot outside it doesn’t take too long.
something just seems odd.

I’ve cleaned the throttle body top to bottom, reset the aic as
turning in key
unplug aic
Stoo eng
Plugin
start engine
and that made some good improvements, but not too much. Hard to explain.

this car lives in a outside garage and doesn’t get colder than 55 at night 80 + in the day.

I have a heated o2 sensor
all vacuum lines have been replaced and are tight.

when I replaced the o2 sensor from an old burnt white crusted o2 sensor, there were little signs of improvement.

Any help on this issue is greatly appreciated. 🙏 thanks!