Update:
I just changed the crankshaft position sensor. The amazon one was a perfect fit. It even had the identical Porsche part number (starting with “986”) printed on the wiring. The Bosch part number on this part was 0 261 210 204.
Here’s the Amazon link to the CPS that I got:
https://www.amazon.com/dp/B006K8ZHOU/ref=cm_sw_r_cp_tai_RgX5CbCN2PCFT
Car seems running great, but putting some more time on it is necessary to confirm 100% that the problem is fixed.
Notes on the installation process:
1. Jack up right rear of car - in front of tire is where I jack
2. Remove right rear wheel
3. Put jack stand under right rear diagonal piece, (directly below where cast aluminum support bolts to it.)
4. Underneath the car, remove oxygen sensor bracket (5mm Allen head bolt I think). Can leave oxygen sensor installed.
5. Unbolt bracket holding oxygen sensor wiring to rear of cylinder head (small 10mm bolt head) - this lets the oxygen sensor wiring swing out of the way to allow good access the CPS bolt.
6. Using 5mm Allen head bit with extension, reach in behind cylinder head to the recess where the bolt is. The bolt is above the cylindrical CPS body. Loosen bolt and remove. Careful not to drop the bolt.
7. Disconnecting the wiring was a bit tricky. There was a bracket the connector slides into. Hard to see.
8. Reinstall CPS, reconnect the wiring and reinstall the oxygen sensor wiring brackets, etc.
That’s it!