Question About Weld-In Wideband O2 Sensor

For those of you who have welded in a bung for a wideband O2 sensor, how long was the bung? Does the sensor extend out of the end of the bung when it is screwed in all the way?

I have an Innovate LC-1 wideband (which I'm very happy with, btw). For a couple of months, I ran it in the rear O2 sensor spot with no problems. But, just on account of it being more accurate, I decided to have a bung welded into the pipe further upstream. I had the midpipe out anyways during my recent motor swap.

I used the bung included in the Innovate kit. However, I noticed that the wideband sensor doesn't extend out past the end of the bung once it is screwed in all the way. It is flush with the end of it, at best. I thought this might be by design so that the readings won't jump all over everywhere from the exhaust turbulence.

Well.....the readings jump all over everywhere anyway....at idle, it will go from 10 all the way up to 18ish. At part throttle cruising, it will vary similar amounts. At WOT, it shows it being VERY rich (7-8 kind of rich), and there's no way the car is running like it is being that rich. Getting on and off the throttle will cause it to vary from full lean to full rich.

So, is the fact that the sensor isn't extending out past the bung causing this? Or do I have problems elsewhere?

It is welded in the 1 o'clock position roughly at the same spot as the front O2 sensor, which is 6ish inches back from the collector. I was under the impression that this is where it needed to be.

Stumbaugh said:

I have the same wideband. I took the bung and cut it almost in half, then welded it on. Works flawlessly.

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Yea, it worked fine in the rear O2 slot, but I could tell it was a little slow reacting. When I go home for Thanksgiving, I'll try and see if there's enough room for an air powered cutting wheel or sawzal, and chop some of it off.

Thought I'd update this. I finally got around to troubleshooting this past weekend. It turns out that it simply needed to be recalibrated. I guess it being unhooked from any power for a couple of weeks (when I swapped in the PI motor) must have gotten it all out of wack. I took it out and recalibrated it, and it now reads perfectly. 14.1-15.2 pretty much all the time, closer to 14.6 at idle or cruising speed, and the same 11.8 that was shown on the dyno. So everything seems fine.