Hello mates,
First of all i agree there are so many post regarding P0420 and i have tried most of the suggested tricks. I am at the end stage to change my Cat. Before doing that decided to check here for the last opinion. So i only get P0420 code on low boost (city driving). If i reset the code and drive motorways no code.
I have changed spark plugs, welded the pipe(funny they found leak on bank 2 after o2 sensor), Cataclean, o2 sensor has been replaced by old owner few months back.
Any other suggestion ?
Thanks