See the section titled, "Hyundai Sonata Timing Chain Information". http://www.partsgeek.com/mmparts/timing_chain/hyundai/sonata.html
From the link, "They are available for the following Hyundai Sonata years: 2015, 2014, 2013, 2012, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000".
So you're right, 2003 was not the transition point to a timing chain, 2000 was.
Here is a link to a 2002 Sonata timing chain:
http://www.partsgeek.com/catalog/2002/hyundai/sonata/engine_mechanical/timing_chain.html
This engine does use a timing belt.
Further comment posting to this review has been disabled by the site admin
16th Mar 2016, 20:05
See the section titled, "Hyundai Sonata Timing Chain Information". http://www.partsgeek.com/mmparts/timing_chain/hyundai/sonata.html
From the link, "They are available for the following Hyundai Sonata years: 2015, 2014, 2013, 2012, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000".
So you're right, 2003 was not the transition point to a timing chain, 2000 was.
Here is a link to a 2002 Sonata timing chain:
http://www.partsgeek.com/catalog/2002/hyundai/sonata/engine_mechanical/timing_chain.html