AlanFowler

Thanks yet again GVK.
I will have to look at that 2.2 ASAP to see which type of EGR it has and hope that just maybe, its not the motorised type with gas-flow sensing. When they fail, is it due to mechanical sticking again or is it the electrics sometimes? Pity there is no way to 'fiddle' the feedback signal somehow.

If you can post any pin data for these then that would be much appreciated. I would guess that on the motorised version there will be a motor drive wire (maybe 12v?), a ground, 2 for the flow sensor and maybe a valve-position sensor wire again (or perhaps a +5v).

Thanks also GVK for the edits which answered my question about the roles played by the various sensors, thereby answering the final question in my previous contribution (these systems certainly seem to be getting frighteningly complex and expensive). It looks as though perhaps with a blanking plate fitted, the 3 pin vac type can still recognise that maf flow does not change when the egr valve position signal is saying that the valve has opened and perhaps this is what turns the eml on, after all. What a pain! Does this sound right to you?