so I recently notice that my car idles at 1K rpm steady after warmed up and driven for a while. With AC off. Searched on forums but couldn't find any details about it. Any ideas?

 

Check for cracks in your intake couplers; the coupler that is attached to the MAF and the one connected to the throttle body. Also, clean your MAF. If there are cracks in the couplers it's introducing unmetered air and that can cause idle issues.

 

Look up "Idle Air Relearn" on here, doing it might help get back down to where you want to be.

 

Well I happened after a engine swap. The intake was good no tears that I didn't notice while putting it back together