Bank one is the one in the very front of the motor basically next to the fan on the motor. easy to see and access
Bank one sensor one on a 2006 Ram is before the catalytic converter on the driver side.
On a 2006 Dodge Dakota bank 1 sensor 1 is driver side above the catalytic converter.
which sensor is for bank 1 sensor 1 on a 2006 nissan xterra
Trouble code P0141 means:O2 sensor heater circuit malfunction (Bank 1 Sensor 2)
That is the sensor in the catalytic converter.
In the Hyundai world bank one is always the firewall side, also called "right" side.
bank 2 is the drivers side of the engine sensor 1 is before the exhaust enters the catalytic converter
Trouble code P1154 means: HO2S-21 (Bank 2 Sensor 1) Transition Time Switch
That means that your o2 sensor is stuck lean (bank 1 sensor 1)
The one after the catalytic converter.
Bank one is the same side as cylinder one, this varies per manufacturer, but is generally on the passengers side of the car, so bank two would be opposite, then sensor 2 would be AFTER the catalytic converter, or post converter O2 sensor. Follow the exhaust to, or just past the catalytic converter and it will be the only thing connected to the exhaust with wires on it.