u/bish68wombat

I’ve tried 3 different OBD readers on my 2002 beetle 1.6l and none work. They either can’t read or I can’t find the right software. Granted the OBD readers are those small ones that connect via mobile phone so that could be the problem. Has anyone found a reader that works correctly? Happy to know brands and plugins required. Also I have an aftermarket stereo with the power cables swapped I heard that can effect the reader? Is that true?