remove intake assy and its inside the engine block,you can see once you remove the intake.its bank 1 aND BANK 2
bank 2 sensor 2 is the passenger side, rear sensor, it is located behide the catalytic converter.
there are 4. here is one of them Bank 2 sensor 1 http://inlinethumb15.webshots.com/4942/2695479270043892667S600x600Q85.jpg
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.
Bank 1 refers to the location of the bank of cylinders that contain the #1 cylinder. Sensor 2 refers to the Oxygen sensor after the catalytic converter. Bank 1 is the left side of the engine, in this case against the firewall, and Sensor 2 is past the catalytic converter on that bank.
bank one is drivers side, sensor 2 is rear O2 sensor(oxygen sensors are screwed into exhaust pipes)
where is the oxygen sensor location on a 1998 explorer bank 2 sensor
Drivers side after cat.
I've posted several photos of bank 1 sensor 1 & 2 on the mpvclub.com website. Bank 1 sensor 1 is nearly impossible without the right tools.
location right bank knock sensor 2003 5.3 z71
The oxygen sensor for bank 1 sensor 1 for a 2000 mercury mountaineer is on the cylinder #1 side.
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