I went to polution test site. Codes P0133 and U0D00 came up. I think the first code is an O2 sensor.

Any u code means one or more modules are not comnunicating on the data lines. These are called twisted pair wires, as they are actually two wires twisted around each other. Hyundai service should be able to tell you what your code is, but without the right test equipment, tracking down what mods are involved will be near impossible.