O2 sensor bung

[Tom Gahman]

Where should I place my O2 sensors for a wide band meter?
After the merge section there is only 3.5 inches to the collector flange on my headers,but
from the flange to the mufflers I have about 14 inches.
What would be the best position?
Engine is a 390 with Crites headers.
Thanks,Tom.

[LuxurySportCoupe]

I've heard you'll get the most accurate reading with the bung in one of the primary pipes. The only downside is that you're only seeing a reading from one cylinder rather than the whole bank.

[thatdarncat]

I don't know if it's the best spot, but my REF headers have the bung 2 inches past the merge. But total length of the collectors is 8 inches.

[drdano]

In an easy-to-get-to spot downstream of the collector a few inches.  Obviously, dont put the sensor on the bottom of the pipe, not just for ground clearance reasons but also to keep condensation from collecting in it.  I have mine in the passenger pipe at 9 o'clock a few inches past the collector and it works great.

[Tom Gahman]

pretty much what I thought, thanks for the replies.
I'll post what I come up with.
Thanks, Tom.