Monitoring Lambda using Alfadiag

[156and33]

Hi

Got a 2002 156 2.0 JTS. ECUs MED7.1.1, CFC208F.
Just fitted all new: ignition coils, lambda sensors and maniverter.  Car running nicely - still does 0-100 klm in ~8 sec.

Would like to confirm correct fuel injection/monitoring system/cat using ALFADIAG to record lambda output as I spent a load of cash.

I have used an AFR meter to help tune the weber on my Pajero, but this is the first time I have used ALFADIAG software to test anything on the 156. Unfortunately I do not have data prior to the cat meltdown and the data looks funny to me (compared to what I have seen from my other scantool on the Pajero).

I have tried monitoring all sensors with the word "lambda" in the name but do not see the pre-cat sensor outputs cycling (~1/sec) between 0.1 and 0.9v (indicative of closed loop function) at idle or constant speed, for any.  The values are always off scale in the graph for lambda pre-cat volts Bank 1 (1.5<>2.2v), which I think is the appropriate output to monitor.

The post cat lambda voltage Bank 1 output is virtually zero at idle but at cruising speed quite high but relatively stable (.25v).

Outputs plotted for bank1 and bank2 are identical.

Firstly, can someone confirm that lambda voltage is the correct output to monitor?
Secondly, why is the pre-cat output greater than 1v?
What do I look at to confirm that the engine is still in lean-burn mode at low rpms?

I have not been able to find any posts which provide a description of normal engine sensor outputs expected from each of the available sensors in ALFADIAG on any forum.  Could someone do this ?  I purchased the Haynes OBDII book to go with the software but it doesn't really provide me with much useful theory.

Thanks