Manual or auto box?
I had very similar problem with Porsche auto (Tiptronic) before I sold it recently. Sudden power loss as though run out of petrol instantaneously, kick in the back as power comes back. No need to change gear for problem to appear but so intermittent that you couldn't reproduce it. Sometimes moving off from traffic lights other times when asking for more power to overtake so potentially very dangerous.
Initial diagnostics indicated possible gear box problem. Error codes came up as low oil pressure registered by 2 of the 6 solenoids on the gearbox control plate. Cleared error codes and they didn't come back even though problem did. No, I didn't understand any of that either!
Apparently not gear box as eventually after a lot of test driving by the Porsche Indy over several weeks resulted in MAF replaced. Seemed to cure it but I only drove it 50 miles and a little round town after that before selling it and it flew with no issues.
Worth loking at MAF and O2 sensors which can produce symptoms like yours. With Porsche you can drive it without MAF for 30 miles or so without issues and if no problem may indicate the MAF needs cleaning/replacing.
Good luck. Diagnosis can be tricky as it could be many things. I am not mechanically minded so I have to trust in the experts!
