After Blow Enable
WARNING: This page is about a different car, the 2001 Pontiac Bonneville and 2000 Pontiac Bonneville. However, it is still accessible from the selected car via links, so may be relevant.
Connect scan tool and turn ignition on. Select INSTRUMENT PANEL MODULE, select SPECIAL FUNCTIONS, select SET OPTIONS and select AFTERBLOW. Select YES to enable after blow. Disconnect scan tool.