OBD II Port — Episode 2: No more 'Check Engine' light blues

Phillip Torrone, in MAKE magazine (Volume 3) raved about the AutoTap Diagnostic Scanner, which attaches to your car's OBD II port and displays "Diagnostic Trouble Code (DTC) and what it means."

Compared to $100 a pop to have your "Check Engine" light turned off — and that's not counting the time and trouble involved in taking your car in — $199.95 might not be unreasonable.