James, thanks for your repy,
The sensor is a four wire zirconia sensor. 2 white heater wires, one black signal wire and a grey signal ground. The sensor was piping hot when I got an output from it disconected, it was not switching as it was out of the loop!
With the sensor conected there was no switching. It just stayed at 1.6v. I saw no point in conecting the scope as I have a fast DMM which would detect the 1Hz cycle rate. Unless I've overlooked something.
I was unable to look at fuel trim with my KTS. I may have the opportunity again next Tuesday to look at the vehicle.
Fast idle emissions:-
CO = 1.37 / HC = 739 / Lambda = 0.948 / sorry no oxygen info.
Many thanks,
Kieron