o2 sensor bung

[Red88]

Hey what's everyone doing about this in their m30 swap? I am using e34 downpipes and am trying to use the e30 exhaust system. Can I put an o2 bung in just one exhaust tube?

[Doughnut]

Sure!

Mine was actually placed right in the collector where the two pipes join.

[Red88]

Is that a collector under the heat shielding just behind where the downpipes start to bend upwards? If so ill do my best to put it there!

[navytapaul]

Yes it is, think more like an x pipe. The exhaust shop cut my collector in half when they did my exhaust, so I just had one put in the side of my exhaust facing outwards.

[ttrousdell]

In my swaps i always put it in the middle of the X pipe so it can sniff both cylinders 1-3 and 4-6 evenly.

[Bearmw]

Wherever you put it try to have it positioned between 9 and 3 oclock so it doesn't contact a lot of moisture like it would if it were placed near the bottom of a pipe.

[Red88]

Cool. Ill have a look in the morning! Thanks felas

[Red88]

For future reference, here's what a stock e30 o2 sensor bung looks like welded into e30 m30 downpipes... About 1/4" gap that needed to be filled because of the discrepancy in tubing size

[Doughnut]

For future reference, here's what a stock e30 o2 sensor bung looks like welded into e30 m30 downpipes... About 1/4" gap that needed to be filled because of the discrepancy in tubing size

Err...

Is the sensor going to receive exhaust gas free flowing over it in that configuration?

Ideal location is directly in the gas path, not beside it.

[Red88]

I do not know how well it flows. We cut about 1/2" across oval into both tubes. We used the bung from stock 325i downp