2013 ford expedition xlt

I have some issues with my 2013 ford expedition xlt. that I can’t seem to figure out and I’m trying to before I just give up and pay $250 to get a diagnostic done on it. The codes that are showing for me are p0306 p0420 and p0430 and suggested I change the spark plug on cylinder 6 and the ignition coil on that cylinder. I went ahead and changed all the spark plugs and the coil on cylinder 6. I reset the computer and drove it for a while but the check engine light came back on and the same codes are being scanned along with the same issue. Whenever I accelerate before 60 mph it’s fine and works properly. But when I try to accelerate especially up inclines/hills my acceleration is non existent and the car begins to shake and the check engine will flash for about 30 seconds. What else could possibly be causing these codes/issues with my car?hav before this most recent work that I just explained earlier, I also have already changed my o2 sensors on both sides(since I previously had that code show along with the ones that I have now). Any ideas of what else could be wrong? And is it likely that the converters need to be changed? I sure hope not. I don’t have the rotten egg smell coming from the car or the black smoke which are tell tell signs of a bad catalytic converter if I’m not mistaken