Just because there is no restrictions at the catylitic converter doesn’t mean the converter is good. The code is reporting that the converter isn’t doing it’s job and it’s not eliminating raw gasses. As stated above, that doesn’t necessarily mean the converter is bad, but it was running more raw fuel through it due to the misfire. The misfire along with the current code indicates that the converter was damaged by the misfire. That being said, just because that is the most likely fault doesn’t mean that you go ahead and change the converter. You should check all of the conditions listed by @richard Kirshey first. You can use a thermal gun and record the temperature in front and back of the converter. It should be hotter in the rear. Using a scanner to read the downstream O2 sensor activity would be a great way to diagnose this also. But the converter is the first suspect.