It depends on the vehicle. It will be the bank that includes cylinder #1.
Right
#1 cylinder is on the left side so bank 2 is the right side sensor 1 is before the cat sensor 2 is after the cat
There are three 02 sensors. The front left sensor is the forward most sensor, on the left bank of the engine. The next is the front right sensor on the right bank, the rear sensor is after the catalytic convertor. see below web site: http://www.courtesyparts.com/A32_O2-sensors.html
Bank 1 Sensor 1- driver's side exhaust pipe Bank 1 Sensor 2-right before catalytic converter Bank 1 Sensor 3- right after catalytic converter Bank 1 Sensor 1- passenger side exhaust pipe Bank 1 Sensor 1- driver's side exhaust pipe Bank 1 Sensor 2-right before catalytic converter Bank 1 Sensor 3- right after catalytic converter Bank 2 Sensor 1- passenger side exhaust pipe
Left and right oxygen sensor not working.Toyota camry 6 cyl,1999
If you're looking at the motor from its relative back-side, Bank 1 refers to the left cylinder bank, Bank 2 refers to the right side, Sensor 1 is pre-catalytic converter and Sensor 2 is post-catalytic converter.
Assuming this is a 3.0 engine, bank 2 would be the three cylinders up front (2,4,6). Bank 1 would be the three cylinders in back (1,3,5). So bank 2 sensor 1 is the O2 sensor right up front that you can see easily.
Bank 1 is on the same side as #1 cyl (right/passenger) side, bank 2 is the left/driver side. Sensor #1 is BEFORE the cat. convertor, sensor #2 is BEHIND the cat, so Bank 1, sensor 2 is the sensor BEHIND the convertor, on the left/driver side. bank 1 is actually on the drivers side
On 2000-2002 Tundra the Bank 1 Sensor 1 is located on the most front left side (your left sitting in the drivers seat). Right next to the rear end of the exhaust manifold, immediately ahead of the flange for the exhaust pip Fault Code PO155 02 Sensor Heater Fault (Bank 1 Sensor 1)
Bank 1 is always the bank where cylinder No. 1 is, or in this case, the driver's side (left) bank, and Bank 2 is the opposite (right) bank. After the point where the pipes meet, everything is Bank 1. Now, counting O2 sensors. One is located by the left manifold, which is Bank 1, Sensor 1 (scanner shows B1-S1). Moving back, the sensor in front of the catalytic converter after the Y-pipe is Bank 1, Sensor 2. After the Y, it's all Bank 1, but we still count the sensor in the manifold as 1. So now the sensor behind the catalytic converter is Bank 1, Sensor 3 (scanner shows B1-S3). On a dual exhaust system, the banks stay 1 and 2 all the way back. For example, on the same truck with dual exhaust ... Bank 1, Sensor 1 is in the left manifold; Bank 2, Sensor 1 is at the right manifold; Bank 1, Sensor 2 is behind the driver's side converter; and Bank 2, Sensor 2 is behind the passenger side converter. If automotive engineers decide to add more O2 sensors, they will continue the numbering in this fashion.
The bank 1 sensor 1 oxygen sensor on a 2002 Honda Accord is located on the header. It is right next to the sensor circuit.
Bank 2 Sensor 1 located downstream left front rear side.