drivers side before the converter
there are 4. here is one of them Bank 2 sensor 1 http://inlinethumb15.webshots.com/4942/2695479270043892667S600x600Q85.jpg
Bank 2 locates on the opposite side of the cylinder # 1 and the sensor 1 is locates in the front
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)
There are 2 catalytic converters on a V8 2002 Toyota Tundra. Bank 1 is the manifold and cat on the drivers side and bank 2 is the manifold and cat on the passenger side. Sensor 1 is the sensor on the exhaust manifold before the catalytic converter. Sensor 2 is the sensor located after the cat converter. Bank 2 Sensor 2 is the sensor located after the catalytic coverter on the passenger side.
if it is a V8 bank 2 is on the right (passenger side). sensor 1 is before the catalytic converter (sensor 2 is after)
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.
The bank 1 oxygen sensor on a 2003 Ford Taurus is located on the motor. It is on the top, back part near the firewall.
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.
driver side first o2 sensor
Bank one is the driver side on a 3.7L. There will be an upstream ( sensor 1 ) and a downstream ( sensor 2 ).
Upstream, driver side.
On a 2003 Toyota ( Tacoma / Tundra ) bank 1 is the PASSENGER SIDE of the 3.4 liter DOHC , V6 engine