Thanks Chuck.

All the information and software I have, has been generated for the US market and I even subscribe to www.Alldata.com. The closest vehicle data which matches my car is for a 1990. 300ce with the 3.0 litre 24v 104.980 engine but Kat and lambda fitted.

As for the 300e (103 engine) car I tested, it was just to give me some confidence that the EHA current measurements for an open loop system made some sort of sense, unlike my own 104.

I take it that on any system the KOEO state should be in specification/tolerance, or bearing in mind that all the other senses should be providing active data apart from the inductive type sensor eg crankshaft position sensor with the ignition on. Or does it need the engine to have been started before the EHA starts to operate actively?

Thanks Tony