I couldn't find any variable resistors, must've chucked them out.
Anyway, I wired the two new connectors together to make a straight-through link, then soldered a 1k resistor across the middle so it's running in parallel with the sensor. Then connected inline with the temp sensor.
When the engines idling hot after a normal run, the sensor itself is roughly 850 ohms, so with the 1k (actually measured at 960 ohm) in parallel this gives around 450 ohm hot, but running in parallel does mean it'll increase a little bit when cold and perhaps smoke slightly less (won't have a huge effect though).
I can't say I've noticed much effect yet, other than a little more soot - mainly when the turbo's spooling up, doesn't seem to smoke much at full throttle over higher revs. Still soots quite a lot more when cold. One side effect I have noticed is that sometimes, when flooring it in higher gears just as the turbo spools up the engine shudders a bit...easy to drive around if you're expecting it but I think I'll disconnect it for the RR day....
If it has made any improvement, it's very slight. It's possibly made it *slightly* more driveable off-boost, but that could equally be due to me having got into the habit of driving more sensibly after ferrying passengers round over Christmas
The mpg reading definitely seems more optimistic, but I think it's misleading.
Next step is to drop down to say, 400 ohm combined and see what happens.
It would be good if someone with a stock, non-chipped 130 could try this and see what gains are to be had; I'm wondering whether being chipped already means I won't see any more useful gains.
Apparently on a stock engine you can replace with sensor with a resistor as low as 150 ohm....