Wideband Placement

I have a 2005 350z and was wondering for correct placement of the AFR wideband sensor. Stock cats are taken out and replaced with Berk test pipes. Each pipe has a secondary bung for a wideband sensor. Would it make a difference if it was mounted on the left or right test pipe? Thanks!

One in each preferably.

I have a 2005 350z too and just bought an Haltech Platinum Pro ECU and two wideband O2 sensors.

The question is, before start tuning: do I replace the narrow band sensors with the wideband ones or is better to drill two holes (and where is the best place to do it) to place them?

Thought I'd commented...

Narrow band have limited usefulness, and basically used to fine tune the OEM ECU to compensate for wear, etc.

With an aftermarket ECU that is going to use wideband, there's no reason to keep the narrow so just pull them and replace with the wide.

[edit] one per bank is best, but if on a budget and/or there's only a single channel in the ECU, you could swap from side to side.