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been reading about oxygen sensors and their need for good connections and not to solder connectors as the sensors receive 'reference air' signals that don't carry across too well or at all if soldered

anyone understand this technological jargon

I think it is along the same lines as oxygen free copper stereo speaker cable

Not quite. For the piezometric element to work it needs a reference of atmospheric O2 levels. One wire sensors normally get this reference through the housing, I believe two and three wire sensors do this also. The problem is that due to the heat in the vicinity of the exhaust the reading is not always 100%.

So basically one of the wires on a 4 and above O2 sensor is your "reference air" signal wire. This is basically a way of keeping the pickup for the O2 reference away from the heat of the exhaust. In real terms there are minimal gains to be made from this.

The reason that you still don't solder the connections of an O2 sensor without the air reference wire is simply that solder won't stick to them! I'm not sure what metal the wire is made from, but its not copper. Most good O2 sensors come with appropriate crimps.

If you're making your own EFI system (which I think you are aren't you?) you'll be best off using a 2 or 3 pin sensor, as these have a heater wire to get the element up to temperature very quickly, giving accurate O2 readings seconds after turning the key.

tim_81coupe wrote:If you're making your own EFI system (which I think you are aren't you?)

Is this a Mega-squirt 2 by any chance?
If it is, please keep us informed of your progress

cough,cough, bloody splutter, can't sleep, cough juice and lollies not bloody working - hence the 3.00am posting

no, I ain't making an efi, just thinking an O2 sensor may help in tuning the gas when turbo instal goes ahead.

a lot of wires are stainless !