Specifically the 2008-on (Euro-4 emissions compliant) 2.2 diesel as fitted to Jaguar X-Type (and Mondeo, Transit, etc.) but I suspect the entire DuraTorq family are the same:
I've seen EGR blanking kits for these, the early (pre-2008) ones blank the EGR totally, the later ones have a ~10mm hole drilled to allow some flow as, apparently, the ECU detects the blanking and throws a fault code.
My question is: How does it detect this, and can it be fooled so the EGR can be totally blanked off?
I'm aware of the implications (positive and negative) of blanking the EGR.