I have a 2005 a6 with the non direct injection FI with no timing belt(the s4 version of the 4.2) and getting a p0430 code. I think ,BUT NOT SURE that the bank2 down stream o2 sensors are:

Bosch 16978
Denso 234-4811
ngk 24603
Herko HK1172
Walker 250-24689

I'm going to assume these are all narrow band o2 sensor with a heater in them (4-wire). What I'm trying to figure out is which one is OEM and does anyone have experience with any of these? One better than the other?

The last Bosch o2 sensor I replaced, I have to reuse my pig tail and cut/splice the connectors.