You can get one at Walmart for ~$70. Just make sure it says it'll clear/erase the code. There are some real cheap ones that just read the code.
Here's one for only $52. It has some software which some website wants you to pay to get more specific info on codes and fixes, but that stuff is free all over the internets. Some of the customer reviews say it shuts off the light with a push of a button.
http://www.walmart.com/ip/Equus-3030-Innova-Diagnostic-Code-Reader-for-OBDII-Vehicles/13029622
Then you'll be able to read the codes and erase 'em and turn off the check engine light in seconds. Even while you're driving without ever lifting the gas pedal.
Mark