Are you saying it flashes when you are moving?
A flashing SES light can indicate a catalytic convertor problem.
Also indicates a random misfire IIRC.
96 T/A, Black/Graphite Leather, T-Tops, 6 speed, 10 speaker Delco/Bose "Monsoon"
Original owner, 217k miles and counting.
Total engine rebuild at 187,020 miles. AIR delete, bored .030 over.
Comp cams Xtreme Energy LT1 266HR-14 street cam and springs.
Custom leather interior at 190k miles. Total repaint 193k Miles