Does any body know anything about this code? Is it just a spark plug replacement or is it a vacuum leak? -- how can I find out?

Thanks

 

Check the #8 spark plug well for water or oil contamination and replace the plug. If it is flooded with oil, the valve cover gasket needs to be replaced. If there is water in there, did you wash the engine?
If the problem still persists, the most likely cause is a failed coil.

It is not a vacuum leak with only this code.