I have the PSE on my 997.1  and PSE on my 997.2 . The .2 is less noisy, one of the reason being the DFI ( actually inside of the car it is far too mute, but from the outside it sounds very nice)  Yes, you can disconnect the brown plug.

Another very good thing with PSE.2 is that you do not see any of the 'black stuff' on your exhaust tips . ( there is much more due to the DFI)


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 997.2 C2S, PDK, -20mm