Lost my...
I use this one on my EEC-IV (1990 F150) works great and easy to use.
Haha you have no clue how hard that made me laugh. I know you can do it with a paperclip but I hate sitting there with a piece of paper writing it down, I always manage to miscount a code or two (because apparently im in preschool and am still learning to count). I ended up getting the OBD1. It was the cheapest so that's what I did.
If its OBD2, and if you have an android phone, get the torque app and this reader:




