Outer Limits 4x4 Board

Can I just weld in a 18x1.5mm nut for an o2 sensor bung? Or will I have to track down a specific 'bung'?

The mounting distance off the exhaust isn't that scientific is it?

And finally, if you don't care about rusting weld, you can weld stainless with standard MIG gear can't you?

ive welded stainless with a standard and had no problems so far

make sure the depth is the same as the standard bung. I cut mine out of scrap commodore 5.7 pipes.

you need to place them in the correct spot - it is pretty important and also different for the type used. on the gen 3 its 1100mm from the flange from memory. They are heat sensitive which is why they have heaters built into them for start up

you can weld stainless with standard wire and it will alloy with the stainless nut and make for a reasonable weld with fairly good anti rust property's.

Thanks guys.

As far as distance goes, I did mean the depth of the bung for the sensor, so how far it penetrates the exhaust. I will try get it all as close as stock.

you can buy the proper bungs from an exhaust shop

i work with stainless everyday and would not us stainless bolts or nuts anywhere near an exhaust also whenever using stainless fasteners always put nickel antiseize on them
it may do the job but good luck if you ever have to undo it

Yeah i'm not using stainless fasteners, the headers are SS and i'm changing the flange type (plus adding o2 bung) hence the SS welding Q.

I only acquired the MIG a while ago (baby sitting it because a mate split with other half) and loving it, I'd only ever had/used my arc welder. It's a good one too I think, an Esab 2000 or something.