Best advice, DON'T use any L293/8 they waste power in the out put transistors!! you lose 2-3v og power. Try a DRV based module there's lots to chose from.
I've used the HCxx04 sensor many times no problems at all. See my bots here: www.melsaunders.co.uk under electronics of course..
But please tell us more about the driver board your bot, a schematic would help, and your code (in tags).
Mel.