Use your $27 to buy a decent manual.
Look at this site:
formatting link
It will tell you how to retrieve the codes with a paper clip, list them for you, and add some decent explanation to the whole thing too. I have never seen the brochure which comes with those commercial $25 code-readers, but I suspect that it's not anywhere as good as what you will find on this site.
The guy who runs this site pushes his own book (that's the main purpose for the site), but I have enough books already and didn't need it, so I would't be able to tell you if it's any good. If it's as good as what he posted, it may be worth the money.