Thanks for the info guys and by the way, anyone building one of Arthur's code readers should be aware that the LED part from Radio Shack is positive/negative sensitive. By that I mean that you must be sure to find out which lead of the LED goes to positive and which to negative. I found out the hard way after building it that I had the LED flip-flopped and so was not working--being a newbie to soldering, circuits, etc., I figured I blew something up in the car!

Anyway, after clearing codes and allowing for "reset", I am getting code 19 from the built-in LED and codes 13 & 20 on pin 8. I've researched what these are but have not found a clearcut answer that guides me in my troubleshooting...hoping someone out there can help!

Thanks as always for the great insight and fabulous resource this forum provides!! Mike