Drinking too much
beer in Munich ;)
Join Date: Feb 2012
Location: I would rather not say
Yes, ideally yoiu want to just blank it off completely, until they find a way to stop the recirculated gas from sticking to the intake walls. It starves the intake charge of oxygen, keeping the temperature down and so the combustion cycle produces less NOx type pollutants.
However, the Alfa ECU is so finely tuned that it knows when it opens the EGR valve that there should be a corresponding drop in airflow over the air mass meter fitted further up the intake. If you just fit a blanking plate in the EGR circuit the volume of air through the main intake is the same when the EGR opens and that is detected as a fault.
The only reason there is a small hole in the blanking plate is to let just enough EGR gas through to cause just enough of a drop in air flow coming in the air intake to fool the ECU into thinking the EGR is working fine. I think that the fact the software is written to allow for a substantial reduction in EGR flow before calling an error is telling of the expectation they have that it will eventually become increasingly blocked. (It's not a finished science yet)
I was wondering if it's an official mod, because mine had one fitted when I picked it up with a 120k miles on the clock after only ever being serviced by the dealer. If not then maybe someone had the care and forethought to fit it to avoid future problems
It would make a great project to mix the EGR signal with the MAF sensor signal to allow the fitting of a blanking plate without the need of a remap.
Last edited by FixitSan; 22-10-12 at 18:55.