Hyundai Repair: P0422 code, o2 sensors, earlyer

Question
I have a 2000 accent GL, question is after earlyer about month ago. I had a code P0722 speed sensor replace both sensors & both 02's upper & lower sensors. Just recently have now the code P0422 should I now replace the catalyst in front of the muffler below? what kind of a job is this going to be if I decide to change this? I appreciate the imformation            Thanks; Ron  

Answer
Hello Ron,
This code usually indicates that exhaust flow inside the converter is below specification. If you replaced the O2 sensors recently that leaves us only one option: Partially restricted converter. I think you should replace your catalytic converter.