where is the diagnostic plug in
 

On a 2002 sonata. It is stumbling now and the check engine light is on. I borrowed a diagnostic reader but can't find the plug in location. Any help would be appreciated.

It's under the dash near the steering column.

2009 Sonata limited
 

Where is the OBD-11 port located on the 2009 Sonata limited

First it's OBD-II, not 11. As in Roman numeral II for 2.

Second, see the post above yours to see where the port is.