turning off check engine

Is there a way to turn off the check engine light myself in a 97 Tahoe without using a scan tool?

Your vehicle has OBD II which is On Board Diagnostics II. This system requires a scan tool to clear any codes that have been stored. You can go to Advance Auto parts and they will clear it for free. A basic scan tool costs about $99. I think it's a good investment as it will work on any car/truck 96 and newer equipped with OBDII. JMHO