I have a 2004 Toyota Corolla. The "check engine"

Hi Al,
The check engine light is to show you that the electronic management system has picked up a fault. It may not be major or on the other hand it may be indicating something serious. Which ever it is,it's a good idea to take the vehicle into a shop and have a diagnosis run on the vehicle. Its better than being stranded somewhere a month or so down the line.
Regards Johngee10