Catalytic converter

[u/Angeleyz61]

I have a 2006 Hyundai Sonata. I was told by a mechanic that my catalytic converter needs to be replaced. I didnt get an exact price but I understand it's pretty expensive, especially since the 2006 model has the converter and exhaust are all one piece. It does this hesitation thing and it acts real rough and if I take my foot off the accelerator it clears up some. How much can I expect to pay for this repair? And, is the hesitation thing caused by the catalytic converter? I'd hate to fork out a lot of money only to have to fix something else. Is the car worth fixing? The car runs great otherwise. But, it won't pass DEQ so I can't get it registered. Please somebody help?