Hecka is word that was originated in NorCal as a more subtle way of saying "Hella".
If you don't know what "Hella/Hecka" means, it is another way of saying "very", "really", or "so".
It is very often used much more often then just for those three words as a replacement.
When said jokingly, people will also say "Heck Of" instead of "Hecka".
"Hecka" is probably the sole most annoying word to say around people from out of Northern California.
If you say "Hecka" around people from other states often, they get annoyed really quick and generally, absolutely suck at trying to use the word correctly... but it is fun to watch them fail miserably at using an awesome word.
It can also be used at the end of a sentence, even though it my sound a little weird, it is still accepted unlike "very", "really", and "so".
You're hecka gay.
I know, sucks hecka.
I bought a hecka lot of donuts this morning fool.
It sucked hecka bad.