Wideband O2 placement wrong?

[QwuickTurbo6]

I have been wondering if my wideband placement in my exhaust is giving me bad data. I decided to weld the bung in the cutout after the downpipe. The problem is there is not a perfect seal where the downpipe slips into the cutout, however the exhuast is leaking out (I dont think fresh air could be getting by the sensor). Will this leak throw off my readings or are they trustworthy? thanks

 

[DailyDrifter]

IMO thats too far away. And fresh air could be getting to the sensor if its not sealed right.

 

[TurboBuRick]

You prolly see afr jumping around allot at lower rpm, like idle and cruise but IMO there will not be much difference at wot.

 

[TR Custom Parts]

Just put a stepped band clamp on that connection to eliminate the leaking.

 

[Chuck Leeper]

A leak WILL put the sensor readings out of whack. There's no difference in introducing air thru a header leak, vs a leak at the cutout joint.. It's still a leak. As far as too far away.. Being it's a heated unit, it does not rely on egt to keep it going. Too much temp, and it'll code on you.

 

[TR Custom Parts]

So what happens if you run with the cutout open????? I have mine mounted in the last bend of the downpipe.

 

[Chuck Leeper]

Too..

So what happens if you run with the cutout open????? I have mine mounted in the last bend of the downpipe.

close to open end of the cutout, and you may see the readings go whacked..Especially at low engine speeds. [Lo eg flow]. Even without leak, @ idle, readings may get "lazy".[Crosscount speed slows]
Try it w/ cutout closed, datalog the sensor. Do it again w/ the cut open.. Do this at idle and WFO... See any differences?

 

[TurboBuRick]

IMO You will not see much difference at wot. The exhaust gases are pushing out so fast, no chance for out side air to get in. The sensor could be clamped to the end of the tale pipe and still give a accurate reading. Dyno shops tune like this all the time.

It's idle and low rpm that allows back pressure to pull outside air into the exhaust and give erratic readings.

 

[TURBO 6]

IMO You will not see much difference at wot. The exhaust gases are pushing out so fast, no chance for out side air to get in. The sensor could be clamped to the end of the tale pipe and still give a accurate reading. Dyno shops tune like this all the time.

It's idle and low rpm that allows back pressure to pull outside air into the exhaust and give erratic readings.

Exactly, there's no way atmospheric pressure is going to overcome exhaust pressure under WOT. My WB is mounted in my dump pipe as well.
And as Mark said, buy a stepped clamp and the leak is gone.

 

[Boost231]

clamp it and be done with it. i have been running a WB in the test pipe for about 2 years now with no problems or weird readings.