This has (most likely) nothing to do with your keyboard layout, so you need no remapping.
Sounds like you spilled your favorite beverage over your keyboard, to be honest.
Does it appear in all applications, or only some? Could you try opening
Applications > Utilities > Terminal and look if it happens there?
Try starting the machine from a boot disk (such as the one included with your Mac). Don't reinstall the OS, but open a Terminal (in the menu bar, I think it's under "Utilities") and try typing. Does this issue appear? If not, it's a problem with your installation.