i got a misfire cyl 6 code a couple time in last 2 weeks.
i have an 03 996 tt with 80k km.
someone told me its likely the coilpacks as they crack all the time,
any other ideas?

 

could be packs, could also be plugs, could be o2's, could be leak in system. Could be fuel. If you have a data logger that reads code check it and see if there are any other codes to go with it. I was getting lots of misfires with a turbo intake hose leak. basically a boost leak. I fixed it and misfires went away.

 

Any maintenance history? Original Coilpacks? When were the plugs replaced last?

 

If the code is coming up on the same cylinder all the time, chances are very good that the problem is actually with that cylinder. I would start by changing the coil on that cylinder. If you haven't changed the plugs in the last year or so, you might as well do them at the same time.

 

Same advice here.... Mostly likely plugs. If replacing them doesn't solve the problem, try swapping a coil with another cylinder. If the misfire follows the coil, then you have a bad coil. Just replace it and you'll be good go. If nothing fixes it, you may have a more serious problem. A bad o2 sensor is possible but that usually will cause all the cylinders on that bank to misfire/run rough as well. Good luck with troubleshooting...

shiv