Need help to identify which O2 sensors are for Bank1 and which are for Bank 2 for my '99 ML 320?

Passenger Side, Driver Side, Before Exhaust and After Exhaust?

I have a pending DTC Code PO156 O2 Circuit, Bank2 Sensor 2.

Advance thanks.

Danny

 

should be left side after catalyst. or also the driver side in usa

 

Thank u "chassis221".
To complete my quest, would Bank 2 Sensor 1 be the sensor before the CAT on the Driver Side???

 

yes
bank 1 is right side bank 2 is left side. sensor 1 is before and sensor 2 is after.

 

Quest complete.
Thanks Chassis221.