Section 410 (Engine Controls Troubleshooting - No Codes - 3.8L): INTERMITTENTS: Preliminary: Definition
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The condition is not currently present but may be indicated in DTC History. Or, there is a customer complaint, but the symptom can not currently be duplicated, if the condition is not DTC related.