99 Intrepid 3.2

Code P 0420 Catalyst 1/1 efficiency below required level.

Other than maybe not passing an emissions test, any harm or potential problems in driving with this situation?

I'm assuming this bad cat was caused by driving around a bit with 2 bad coils and a bad intake gasket.

 

The computer might stay in limp home mode....other than that if the cat doesnt get plugged you should be ok. And yes the 2 bad coils caused the cat to go bad.