O2 sensor location

[BaldMenace]

I have Cruz T4 headers and a Ballenger wideband with NTK o2 sensor. The O2 bung on the headers is right before the turbo mounting flange. I've read it's recommended to put the sensor in the downpipe. Is this correct? I guess I can use the current O2 bung for a back pressure sensor.

 

[Chuck Leeper]

Too hot there.
And it's also affected by higher exh gas pressure.

 

[BaldMenace]

Too hot there.
And it's also affected by higher exh gas pressure.

Makes perfect sense. So why do they put an 02 bung there in the first place?

 

[GNVYUS 1]

That pre flange bung could be for those running the stock 02 sensor and the DP for the wideband. There's an interesting bung rule for DP 02 sensor, ex DP ID so 3" DP = 12" from DP flange.

You can buy a shorty SS bolt and plug the hole, run wideband in the DP.