Code readers are under $20 for a good one.  Most Autoparts stores will read the codes for free, but most will not clear the codes.  Having your own is great.  I've been using this one for years - Autel MS300 Universal OBD2 Scanner Car Code Reader, Turn Off Check Engine Light, Read & Erase Fault Codes, Check Emission Monitor Status CAN Vehicles Diagnostic Scan Tool  $19.99 on amazon.