Pretty sure it is fixed.

My only concern is that the idle switching is a little slow and "occasionly" it sort of hiccoughs at idle and goes rich/lean bigtime (on the exhaust gasses) for a minuite or so before settling down again.

It is Much_better than when I started but I am still concerned that it is "Not quite right" IYSWIM.

I know that the EGR is a possible problem, initially it was throwing codes and the feedback was over 2V at idle/KOEO owing to being clogged up with gunge. Cleaning it has got this down to 1.7V and it no longer throws codes but this is still nearly a volt higher than the feedback signal from a new EGR valve under the same idle/KOEO conditions.

I am lothe to add a new EGR unless I really have to, the guy has already spent a load of dosh on EBAY crap + what I had to fit to get it right and it is still only an old corsa.

But we shall see....

On a more general note, I dont think this is "Just" a scan-tool issue.

Using the scope the "Universal" Lambda gave a "Good" signal, it just wasnt enough to get the ECU to switch. The ECU needed the 1.2V signal from the Genuine(ish) sensor! So what is going on there then?? Is there a shottky diode incorperated in the genuine sensor or something to bump up the output over that which one would normally expect or something??

Ho Humm.

Paul