It's a problem with your bank 2 upstream oxygen sensor. First, call the
dealer back with your vin and have them check to see if there are any
recalls on the vehicle. There was a recall to reprogram the pcm which
addresses this issue. If this hasn't been done, they should be happy to do
it free of charge. If it has already been done and you're beyond the
warranty period, the repairs are your monkey.
Hyundai has had some problems with these oxygen sensors and has made some
attempts to fix the problem. Although they originally appeared to be
working, I still see many failures of this oxygen sensor.
If you'd like to try this job yourself, it's the oxygen sensor in the
front manifold near the top. The part number for the sensor is
39210-3916A, but be aware that the distribution of this sensor is
currently being restricted by Hyundai because they don't have enough to
fill all the orders. I actually checked into the availability of this
part a few days ago and it appears plenty should be available in about a