Durango_Boy

I will have to add an O2 bung to my exhaust. It's already in the plans to switch from the 2 sensors to the single O2 sensor. I have never added one of these to a system, and could use some pointers.

Which bank is best to use, and where, on my Hooker side mount headers should I add this bung?

Also, is there a special kit for this kind of thing or should I just drill a hole and have a nut welded on? What size nut, and what tips or precautions should I watch for? Thanks.

MotorHead

There is a special 02 bung that any good muffler shop should have, the guy that did mine used a torch to make the hole and welded it on in 2 minutes, he was a good welder/fabricator. If it is for a O2 sensor make sure it is welded above the centerline of pipe so condensation doesn't affect it

markdtn

Most headers can be bought now with the bung installed. You can buy the bung and weld it in. Most GM with a single sensor are in the drivers side. You can also use a spark plug anti-fouler and cut it apart to use as a bung.

Durango_Boy

Ok, so driver's side is more common. Where on the headers is a good place? At the collector or after it?

Twin_Turbo

installed in pass. side collector, easy 5 min job. Used stainless bung (it's M18 x 1.5 fine thread)

norvalwilhelm

I have done a number of them and like the drivers side but the last one I did was on the passengers side. There is no advantage to either side.
You can NOT weld a bung into a ceramic coated header. I put mine right at the collector flange in the exhuast pipe. I have a tap for a spark plug so I just use whatever nut is a little smaller then the required hole, weld the nut into place and then pass the proper drill thorugh the center of the nut and then tap the hole.
I mig weld them into place.

I'm Batman

Summit carries O2 bungs, both weld-in and bolt-in.

84rzv500r

I put mine in the number 8 tube on a BBC, Collector is the best place but I didnt want it hanging out the side on sidemounts... if you put it in a tube keep it close to bend from vertical to horizontal to clear the frame... Also the GM docs say that you should mount the sensor no more than 45* from vertical (wire up sensor down).

Just mig weld it in before coating...

chevymans 77

I get mine from the local home center, I use a M18 x 1.5 jam nut, its narrow and it works great. I need to install my meters so I can start tuning the carb.

Neal

carriljc

I use the anti-fouling extensions...cost a couple of bucks for 2 at generic parts places.
I use a hole-saw to make the hole, put a pipe plug in to avoid spatter issues, and then wire-feed weld it on.
On my ceramic headers I ground of some of the coating, welded one on, and then used POR-15 high temp silver afterwards.

mrvette

Why, specifically, is that 45* from vertical wire up a necessity???

the sensor itself, or airflow charactoristics?? and how important IS this....??

shafrs3

Keeps water from collecting in the sensor.

MotorHead

You can get some of the ceramic coating and you brush it on then use a torch to cure it, never done this myself but that is what I was told when I was getting mine coated and wanted to put another bung in the passenger side after.

carriljc

and the followup with the torch to cure.

The Hi-Temp POR-15 seems to be holding up quite well. I actually put an O2 bung on each side. 1 for the ECM and on the other side for A/F ratio meter.

Twin_Turbo

I once did a set of headers with the ceramic stuff and heating them in an oven...it sucks and it's ugly. I cleaned the pipes meticulously but I didn't pre heat them, when curing somehow vapor started to excape leaving an ugly bubble finish:

VetteNut72

Here are some shots of where I put the O2 bung in my sidemounts:





You have to be careful to get the position correct. Too far up and the sensor will hit the frame, too far down and it will be exposed to possible impact.

Here is how mine looks installed:


These pipes are uncured ceramic soooo, I'll let you know how the ceramic painted at the weld area holds up. I am hoping it cures along with the factory applied ceramic coating.

Craig

Durango_Boy

Thanks fort those pics Craig...that was exactly what I needed to see.