Section 270 (Engine Controls Troubleshooting - No Codes - 3.1L): INTERMITTENTS: Preliminary: Definition
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The condition is not currently present but is 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.