Not sure what a squeal only in reverse would be. A common squeal in the Sportage is the power steering belt. But it would make noise when iding, and going forward and backward.
In order to determine the cause of the CEL you'll need to find a mechanic who has an OBD-II code reader or scan tool. That reader will plug into the diagnostic port under the dash. The code, or codes if more than one, will come out in the format PXXXX, where XXXX will be a number. Once those numbers are pulled you can determine what happen.
A source for the code meanings for Sportages can be found here.
Http://www.kiatechinfo.com. While that site is for U.S. spec Sportages the troublecodes mean the same thing across all variants regardless of location. But if you need additional help on diagnosing the meaning of any troublecode post the numbers here.
Linear Mode
