Probably the Idle Air Control valve going bad. You never stated what engine you have (4 or 6 cyl) but I can say from experience that swapping the IAC on the 6 cyl. is easier than changing oil. The part is around $60.
Beer is my Gatorade.
Hooray Beer.
'98 "Sport" Pacific Green
'98 E0 SVT Silver Frost
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