So i have made a slight bit of progress but only with diagnosing the problems.
Basically it is just overfuelling massively. I got an air fuel ration on from the emissions and it was reading 11 constantly.
To put into context, on a working g40 it read 14-15 when running correct. When unplug either blue temp / lambda it reads 13.
so the readings i am getting seem to be bypassing the signal from the sensors. Which leads me to think its a dodgy wire somewhere maybe getting a feed or not earthed right, but which would cause the ecu to ignore/not get the signal?
When you unplug the blue temp sender all the polos i own the rev range raises (when up to temperature), but on my caddy it does not, it is irregular and in some instances it coughs and splutters and runs rubbish, which at least tells me the signal is being read by the ecu, but ignored?
Its a proper head fk this issue, in all my time never seen anything like it.
Ive swapped ECU and every sensor, injectors etc nothing has not been swapped
any ideas would be great
cheers