Thanks for visiting2carpros.com. This may be one of two things or a combination of both.
1 A vacuum leak
2 A sticking idle air control valve.
I'll post a guide below on checking for vaccuum leaks
https://www.youtube.com/watch?time_continue=5&v=4ktw1X4W_-k
This generation of GM/Saturn vehicles also had very common idle air control valve failures. It is valve that blocks or unblocks a hole in the throttle body to allow engine speed changes independent of the throttle. When they fail the symptoms you describe can occur. Replacement is pretty straight forward. It's located on the side of the throttle body. If you follow the intake tube from the air filter you'll find it. I'll post info on that below.
REMOVAL
1. Turn ignition Off.
2. Remove air intake tube and resonator.
3. Remove electrical connector from the IAC valve.
4. Remove screws and IAC valve.
NOTE:
The IAC valve is an electrical component and must not be soaked in any liquid solvent; otherwise damage could result.
5. Remove O-ring from IAC valve and discard.
INSTALLATION
1. Clean the IAC valve seating surfaces on the throttle body to assure proper seal of the new O-ring and contact of the IAC valve flange.
2. Lubricate new Oring with clean engine oil and install on IAC valve.
3. Insert IAC valve in throttle body.
4. Install IAC valve attaching screws using thread coating, Saturn P/N 21485277 (Loctite 242 Threadlocker or equivalent).
Torque: 3 NM (27 in. lbs)
5. Connect electrical connector to IAC valve. Push in connector until a click is heard and pull back to confirm a positive engagement.
Image (Click to make bigger)
SPONSORED LINKS
Sunday, January 27th, 2019 AT 6:07 PM