sux to be u man... lols well i ve changed sparks 4 months ago and have exactly what u have...

and i ve got no clue what it can be.... i guess the only thing i ve got left to do is change the sparks back and think the new plugs were factory damaged or something....

even tho i can suggest i damaged coils but it seems to be petrol problem and not separate cyllinder...

anyways what ive done is described above... so far its not going better