Just to add to the mix.
I have the 156 16v jtd 150bhp engine.
The egr requires 2 blanking plates one at the bottom (oval) and one to the manifold (rectangular), surely the egr and fittments are the same??
I could be wrong, thought I should add my 5pence worth.
No EML light with both blanks fitted.
That's completely correct.
I posed the question in the other thread, so I may as well finish it here.
The exhaust gases flow up through the oval shaped gasket entrance into the EGR, and from there into the inlet manifold.
If you just restrict the inlet manifold side (the rectangular one with four holes, one in each corner) you will obviously increase the build-up of soot in the EGR valve, as the oval entrance isn't restricted (the exhaust fumes will pour into the unrestricted EGR, but will be restricted in the EGR due to the inlet manifold restrictor gasket).
Consequently, you need to use the oval restrictor plate with the three central holes, this is also available from the Alfa dealers. There is a single hole version with 9mm diameter available from places such as ebay but this often throws the light on - it's too restrictive (there is isn't sufficient gases to 'trick' the ECU).
Use the metal gasket either side of the three hole restrictor plate to get a good tight fit.
Did all this with my new EGR valve on my 156 JTD 16v 150, no problems. If anything delivery is smoother through the rev range and perhaps more urge through the gears, but this could be a placebo effect.
Either way, you know that with both restrictor plates, both the EGR valve and the inlet manifold will suffer less from soot build-up.
What I would not do is just fit the rectangular restrictor plate. Please tell me what kind of condition the EGR will be in even after a short while if you do that?