The cables are 'cheap' however, its the actual software bought from a company called 'Ross-Tech' that is the costly bit.
Things like 'Scangauge II', 'LiquidLogic Gauge' and now the
OBD II Bluetooth adaptor with the 'Torque' Android app, will allow you to read/reset fault codes and run 'live' data gauges. These to be honest, would get my vote.......as it allows you to self diagnose and inform us all of specific logs to solve your issues!
Jimski