Depending on how it is built, LS/VTEC hybrid engines usually don't have knock sensors. The high compression ratio is what is causing it, the highest C/R I would use in a street car would be 11.5/1 but I ave heard of higher. In the worst case scenario, the engine will need a total rebuild/replacement. The amount of damage depends on how hard it pings, and how long the guy drove it like that.