the reader's are expensive.....got a paperclip?
Under the dash on the glove box side is a small blue plug. just off the floor/firewall. The plug secures to something up there, but doesn't lead anywhere else.
Pull it down. With the car off insert the paperclip into each side of the plug.
Turn the car to on, and count the blinks of the check engine light.
If the code is two digits it should flash at a different pace for the first digit and then the second. To be sure, turn the car off and on a couple times til your confident you have the right code.
I think you can reference the shop manual in the FAQ to determine your problem, or just post it here and someone will chime in!