Code 0430 and 0420

For those that have seen my previous posts, let me apologize for beating a dead horse.
I have been getting a 0430 code (catalyst efficiency out of spec in bank
2) and I have just been clearing it or waiting for it to go away. Last night, I determined that it wasn't going to go away on its own and I pulled out the tool to clear it. What I found concerned me: not only did I have the 0430, I also had a 0420- the same problem in bank 1.
Q1: If I've worn out a catalytic converter in bank 2, is there any way that can cause bank 1 to start having problems? (I was pretty sure dual exhaust wouldn't allow for this)
Q2: By just clearing the codes and not fixing the problem, am I doing damage to my car?
Thanks-
1996 T-bird, 4.6L, original owner, 140K miles (I fully expect it to make 200K+)
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As I explained before, there are a number of things that will cause a cat converter efficiency code. They all need to be followed up on to find out why the code keeps being set. In the long run, yes, you run the risk of having to replace them. I can guaranty it will be costlier than, oh lets say replacing a bad fuel pressure regulator.

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