Will a new sensor correct the P0420 bank 1 code?

The P0420 code indicates a problem with the catalytic converter's efficiency on bank 1, which may be due to a faulty catalytic converter, oxygen sensors, or exhaust leaks. Replacing a sensor, such as the upstream or downstream oxygen sensor, may resolve the issue if the sensor is indeed faulty. However, if the catalytic converter itself is the problem, simply replacing a sensor will not fix the code. It's essential to diagnose the root cause before making replacements.