The light flashing 8 time means that the computer is getting invalid wheel speed information. This could be mismatched tires (2 new tires on one axle with 2 old tires on the other) or even 2 different size tires. Or could even be a bad wheel speed sensor. You need to get somebody with a scan tool to see if they can pull the codes for you. A parts house normally will do this for free.
