2004 Hyundai Sonata PO130 Code

The O2 sensors are they OEM parts?

A code P0130 may mean that one or more of the following has happened:

The oxygen sensor is faulty
The wiring to the sensor is broken / frayed
There is an exhaust leak
Possible Solutions: The simplest thing to do is to reset the code and see if it comes back.

If the code comes back, the problem is more than likely the front Bank 1 oxygen sensor. You will likely wind up replacing it but you should also consider these possible solutions:

Check and fix any exhaust leaks
Check for wiring problems (shorted, frayed wires)
Check the frequency and amplitude of the oxygen sensor (advanced)
Check for a deteriorating / contaminated oxygen sensor, replace if necessary
Check for inlet air leaks
Check the MAF sensor for proper operation

Hyundai uses similar electronics to BMW and this issue can be due to software. A possible reflash could be the solution.