I have a friend with a 996 C2. He told me that he went to a shop in order to install a board switch for the PSE. So i dont think PSE has a switch form the factory. It opens and closes automatically as you press/release the throttle

 

My 2003 C4S has PSE with a button. Some cars I've read come without the button.

One thing to note is that whether you have the button or not, there is a cut out at low speed where the PSE goes quiet. There are a few things you can do to stop it from cutting out at low speed. I chose to remove the capacitor from the relay.

Here is a good thread about this:
http://www.pistonheads.com/gassing/t...t=834498&mid=0

 

That's not correct. I have checked with my Porsche dealer, and the 996 "generation 2" (from 2002) was produced for a few months with PSE but without the button to switch between quiet / loud. (Which is indeed the case with my very early C4S.)

If you have the car's VIN code, it's easy to check if the car has PSE, for example on this site: http://www.autoatlanta.com/life/vin/vin.php

 

Interesting fact. I've never heard of that before...

 

Absolutely right... as I said earlier that was the way my C4S came and I did a VIN check to confirm.... easiest way to disconnect the solenoid that controls the valve is to unplug it..(orange plug RHS in the engine bay). Takes 30 seconds and if you don't like it... plug it back in....