Any ideas ... Misfire Cyl 1 and 3

[chris97boxster]

I'm staying away from mohawk/husky 94
ethanol has its cons
when I was in montana
a lot of places were advertising premium without ethanol

I only fill up @ shell now
odd time @ esso

I'm running iridium no issues with plugs
going back to CU copper core would b a step backwards IMO

I ran a tank of 94 from husky & it t threw O2 codes
that's when I changed plugs

I like jake d 's idea if u have coil/wire problem
but I would do plugs 1st

Chris

[Steve Tinker]

Why would you change the type / spec of the spark plugs from what Porsche recommend - and pay a hefty premium for them to boot?
Running non spec plugs is worse than using the wrong oil - if it goes wrong, you can have serious problems !!

If you have a missfire & you don't know the history, go back to basics and change all 6 plugs to either Beru or Bosch as per Porsche recommendations. While you have the coils unplugged and on the bench, check visually for corrosion and cracking - if in doubt, replace.
If they look OK, swap the suspect coils with good ones from other bank, clear fault codes and start the car - if the fault codes follow the suspect coils then you have your answer....