P0037 Toyota - sienna 2007

Question

The P0037 error code is for Bank1 - Sensor 2. It is a bit confusing as some sites I have looked at will say right or left side, front or rear and I also see upstream and downstream.

Bank 1 is for the engine side that has cylinder 1, while bank 2 is for opposite cylinder 1.

If I have interpreted it correctly the left side is the front of the engine (closest to the rad) and right is the back (closest to the firewall).

Upstream is before the catalytic converter and downstream is after it.

So I think that Bank 1 Sensor 2 is on the right side (firewall side) downstream (after catalytic converter.

So the part I would order is Downstream right or also could be downstream rear. Correct?

Answer 1

Correct Bank 1 Sensor 2 is on the right side (firewall side) downstream (after catalytic converter)

sensor 1 is called air to fuel ratio sensor 

and 

sensor 2 is called oxygen sensor

denso part number is 234-4512