Volkswagen Forum - VW Forums for Volkwagen enthusiasts - 99 Beetle 1.8T

Hi y'all, new to the forum here, I've got a 1999 Beetle 1.8 Turbo with LOADS of problems, LOL.... was running ok when I got it, but needed a coil pack according to a misfire code it was throwing.

I replaced the coil pack, and then kept getting codes for other cyl. misfires... so I replaced ALL the coil packs. - Still was having issues, replaced spark plugs, air filter, etc. and still having issues making it un-drivable, it doesnt have enough power to get about 20mph and is running SUPER rough. I have attached a video showing how it's running, and I am ruling out major engine damage because if I put new spark plugs in it, it literally runs smooth and perfect for about 20 minutes... then right back to this again, and eventually will start throwing misfire codes again. - Nothing I do can keep this thing running right...

I am suspecting something is wrong, a sensor, something that is telling the computer to make it run bad.... but where to start? I can't just start replacing stuff, not having a clue where to begin! hopefully someone can help! :)

here's the video...

thanks so much!