I have a like-new OT-2 datalogger/obd2 reader that works with PC or iPhone through USB or WiFi connection. Really nifty tool and easy to use. See data realtime, program specific data to log, and the usual DTC code reading/clearing features. I have no apple iPhone as or iPods anymore, and they don't support android, so my loss. I bought it new and still have the box.
Asking $75
http://www.ot-2.com