OBDII fault code P1186 which O2 sensor?

[bbojangles]

it tells me this is Bank 1 Sensor 2. which of the 2 sensors is this?

This is on an 1996 318i sedan. check engine light is persistant.

From what I have gathered, it it is the pre-cat sensor, then it needs changing. if it is the post cat sensor, then the likely thing is that the wires fell onto the pipe and melted.

Either way, I would like to know what sensor is generating the fault.
Looking under the car might help, but I would like to be armed with some info first..
thanks

[1991 E30 M42]

Sensor 2 from my experiences normally refers to the post cat o2 sensor.

[ScreamerBeemer]

Sensor 2 bank 1 indicates that bank one is on the same side as cylinder 1. Being a 4 cylinder that makes that easy. Sensor 2 is usually behind the cat as said before. O2 sensors are numbered by how close they are to the engine, the closer to the engine the lower the number.