got a quick question. my 01 ranger stumbles for a few minutes after its started. once its warmed up the idle smooths out. the only code that comes up is that bank 1 Sensor 2 is malfunctioning. i no that a bad downstream sensor wont affect how the vehicle runs. could this mean that the passengers side catalytic converter is bad? i do get a soft rattling noise from the exhaust. the truck also struggles going up hill. feels like im loosing torque. the sparks plugs and wires have been replaced, both upstream 02 sensors, MAF, and fuel filter. any ideas?