Section 249 (Engine Controls - Trouble Shooting - No Codes): INTERMITTENTS: Notes
WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES - GENERAL MOTORS
article in GENERAL INFORMATION before disconnecting battery.