Topic: exhaust bung for 02 sensors

[tagueyourit]

I have an 84 22r and when I did the exhaust the shop put in the thread bungs for the o2 sensors.  Stock the bungs have bolts.  Do I have to redo my exhaust back to the stock bungs or can I get o2 sensors that will thread

[yoshaleng]

If you use a manifold from a late 2nd gen or a 3rd gen, you can eleminate the bung on the manifold and have your o2 sensors on the bottom....i before the cat and one aftyer the cat.
You can probably cut the bung peice off a vehicle at a wrecking yard.

[emsvitil]

Any 1 wire or 3 wire O2 sensor will work with the 18mm bung.   Just cut off whatever end is on it and replace with toyota wire connector (seperate 2 wire connector for the heater if you go to 3 wire)

I changed my stock 1 wire to a heated 3 wire to make it more reliable (no weirdness at idle as the O2 sensor stays hot)



You crimp the connector on the sensor wire as solder will close up the O2 path that the sensor needs to work correctly (O2 flows between the wire strands to the sensor)

[VincentVanPwn3d]

Nice info, I plan on doing a new exhaust setup on my 84 22r soon too. thx

[yotaneck13]

i actually prefer the o2 in the manifold its out of the way and all

[mt_goat]

You can probably cut the bung peice off a vehicle at a wrecking yard.

Yep, you can salvage one or make a new one from scratch.  I've done both:



Here's how to make your own O2 sensor bung.
I started with a piece of 3/8 steel and marked the outline with a gasket and drilled and tapped some holes (8mm x 1.25):


I used some exhaust studs from the dealer that were left over.
 

Then I started cutting it out with a cutoff wheel on an angle grinder:

After using a grinder and beltsander to smooth it out:


Now that was one bung, but I need two for my 5VZ.  The first one took me about 2-3 hours to make so I decided to try cutting an old one out of my old 3.0 exhaust pipe and using it.  That took about 2-3 hours too, counting replacing the old studs and smoothing it out with a grinder and beltsander too.  

Here's the two side by side, the one I made from scratch will have to be welded in parallel to the pipe since it's not curved to the shape of the pipe:

[OOPS]

You can also go to an exhaust shop and buy them, especally shops that do custom work.

[mt_goat]

You can also go to an exhaust shop and buy them, especally shops that do custom work.

I couldn't find any in the shops around here, but I have seen one guy selling them online after I made those.