Driving it off the cliff

[Stl-986]

The only thing at 12 is the main ground wire that goes over to the SAI pump. Been looking at wiring harnesses and it looks like the one I mentioned by the AOS & corner of the intake are the ground terminals for the coils and other things on bank 1. That is good & secured to the engine. So if it is a wiring issue it is going to be one of the other wires, a break (unlikely since it does fire) or a chafed wire.

[RedTele58]

Originally Posted by Stl-986

So if it is a wiring issue it is going to be one of the other wires, a break (unlikely since it does fire) or a chafed wire.

Remember this from page 2, 10 days ago? Have you looked for this?

"Sorry to be late to the party on this one, but I had an almost exact situation last month with my '02S. Same misfire codes on one bank.
I ended up taking mine to my Indy shop where they discovered a bad #4 ignition coil housing on the engine wiring harness. (which looks to me like the only thing you haven't replace)
They state they use to be able to get just the individual housings, but now Porsche wants to sell the entire engine harness. Fortunately for me, they are still able to source the individual units. (And yes, changing one connector housing cleared all the misfire codes)
You may want to check this out before you completely get lost down the rabbit hole."

You're pretty far down the rabbit hole. Not being smart, just trying to help.