On a 2000 Lincoln Town Car :
Bank1 is the passenger side of the engine
Sensor 2 would be in the exhaust AFTER the exhaust has passed through the catalytic converter ( downstream sensor , also called a catalyst monitor )
The oxygen sensor for bank 1 sensor 1 for a 2000 mercury mountaineer is on the cylinder #1 side.
That should be the sensor after the catalytic converter.
On a 1996 Lincoln Town Car : Bank 2 is the drivers side of the engine
On a 2000 Lincoln LS , 3.9 liter V8 engine : Bank 2 is the drivers side of the engine Sensor 2 is in the exhaust after the exhaust has passed through the catalytic converter ( downstream sensor )
On a 2000 Lincoln Town Car , 4.6 liter V8 engine : Bank 2 is the drivers side of the engine Sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter
Sensor one is in the exhaust manifold on the back of the engine. Sensor two is in the side of the catalytic converter.
bank 2 sensor 2 is the passenger side, rear sensor, it is located behide the catalytic converter.
Bank 1 would be the passenger (right) side of engine. Bank 1 Sensor 2 would be the O2 sensor after the catalytic converter on the passenger side.
On a 2000 Lincoln Navigator : Bank 2 is the drivers side of the engine Sensor 1 would be close to the engine before the exhaust enter the catalytic converter ( upstream sensor ) Sensor 2 ( downstream sensor ) would be in the exhaust after the exhaust exits the catalytic converter
The P0155 refers to the Oxygen sensor on Bank 2, sensor 1. Bank 2 on your vehicle is on the passenger side of the engine. Sensor 1 is the first oxygen sensor in the exhaust pipe coming from the engine.
It is the sensor in the outlet of the catalytic converter.
bank one is drivers side, sensor 2 is rear O2 sensor(oxygen sensors are screwed into exhaust pipes)