someone please reply to this post
P0420 Catalyst Sytem, Bank 1 efficency Below
i checked it with my predator's diagnostic's features. So exactly what is this problem and how can you fix it.
Im thinking its somthing along the lines of a bad 02 or one of her cats has completly gone bad.
sorry for the long post but im pretty mad that they are trying to do this to my girlfriend
i believe thats the SES light i got when i had a bad 02 sensor


