I had one of the China Clone PIWIS or whatever it is called...never worked...$25 thrown away. The least expensive thing you can get to read general codes in the Porsche is a program called "Torque". It is an APP for a Android or IPhone and you will need a Bluetooth adapter that cost around 10 bucks
The full APP is around 6 to 10 bucks.....Money well spent. Before I got my Durametric and I had a engine light come on while driving I could stop and read the code (usually a Catalytic error) and I had no worries about driving it home. The App will even go online and look up the code for you and you can store them on your phone (cloud) and retrieve them later . While it is nowhere a full diagnostic setup for 20 bucks it is money well spent. Forget the Chinese Cable that hacks durametric software...if you want one I have one you can have if you pay shipping....but a coat hanger is just (perhaps more) useful.
Oh and the little blue ELM 327 are so cheap I have one in each car and setup profiles in my phone for each.
V1 5 ELM327 OBD2 Bluetooth Car Wireless Scanner Diagnostic Tool for Android | eBay