it says bank 2 sensor 1

i am sure it is one of the manifold sensors but i don't know which one it is. can someone help me out w/ this?

thank,
ty

A Bimmerforums search for P0103 yields 13. A google search yields more.

It is the oxygen sensor for cylinders 4,5,6, upstream of the cat converter.

o2 sensor for bank 2 (cylinders4,5,6)

yeah, but which one of the 2 o2 sensors above the cat is it?

Don't you have one for cyl 1-3 and another for cyl 4-6?

yes, but i don't know which o2 sensor is for the 4-6 cylinders.

It is the one on the pipe connected to the 4-5-6 exhaust manifold!

#1 is the front of the engine, #6 is closest to the firewall... so the O2 sensor in the back half of the exhaust manifold. The tricky ones are the rear O2 sensors on cars that the wiring can reach either one.