Greetings,

On the current OBD-II electronics in today's cars there is no way to pull a
code without a reader.  Sorry.

However, you can usually go to any local auto parts store and they will read
the codes for free for you.  The problem is that some of the codes and
explanations aren't exactly clear and it's still going to take a qualified
mechanic to fix most of the problems.  Once you get the code(s) you can go
here for a brief explanation of each http://www.troublecodes.net/Kia/ or
http://www.actron.com/code_lookup.php

Since a loose gas cap can also set your check engine light off, the first
and simplest thing is to make sure the cap is tight.  Anything else past
that is going to get more complex.

Cheers - Jonathan

a obdII ready can be found on eBay for under $40. it will give you only the
codes. you can get the meaning at
http://www.kia-forums.com/do-yourself/33370-all-kia-trouble-codes.html. or
disconnect the batery for 5 or more minutes, this will loose the radio
settings that's all. it will reset the computer. if you get a CEL after
that, then act on the information. Mine it was the Idle Air Control.
specifically the connector ground was correded. 2 seconds with some radio
shack contact cleaner, and it's not been a problem since.