I doubt that the sensor is causing the misfire. But since you're getting the CEL for it, it's a cheap fix:
http://www.ecstuning.com/Volkswagen-...sor/ES2535452/
Now, the misfire is caused by a few things. Bad plugs, bad coils, or a vacuum leak of some sort. I'd be willing to bet all of the above :-P. Seriously though, I'd start with a search for vacuum leaks, most likely on your PCV hoses. If they're the originals, I can pretty much guarantee this is the culprit. Check the boost pipes from the turbo down to the intercooler. They tend to come loose, especially the one on the pancake pipe behind your passenger side front wheel.
Does your CEL blink? If so, change out the coils. Spark plugs are cheap enough to change, and if you haven't done it in a while, get some new NGK's and gap them at .028" (BKR7E).



