I pulled the throttle body to clean and replace the seals due to high idle. Now after putting it back in the car had a very low idle. It will start up at around 1900 rpm, then once warm to idle drops to 5-600. Right at the first tick after 0 on the tach. 

I adjusted it up a bit with the IAC screw. Now it's at 750 rpm, but it hunts up and down about 100rpm.

While you were cleaning the throttle body did you clean out the IAC and check to make sure it moved with power applied?Are you sure you have all the sensors and vacuum lines connected?

I cleaned the IAC and it's working because at startup it's idles at 1800-2000 and slowly goes down as it warms up. I don't have any CEL so I don't think and sensors are unplugged.

 

Also I have good vacuum, even at WOT my defroster works. I replaced all the gaskets in the throttle body, and the pvc valve.

 

A new issue is it is hard to start cold. Takes 20 seconds to fire over.

might be worth checking the CTS.  It can fail and not trigger the CEL.