Just a slight correction on the above post.
The exhaust gases are not technically recycled. Exhaust gas has already been burnt, ie. no oxygen content and therefore inert. Modern engines are running so lean at light throttle loads that the combustion temp is raised and NOX is produced. Introducing an inert gas has the effect of enriching the mixture and therefore reducing the combustion temp and NOX emissions. My personal view on these egr failures is that Renault (and most other VA's) have increased the service intervals too far. I am struggling to get the message across to my customers that they should have a service at least every year even though they say "its only done 10,000 miles". I wouldn't mind betting that your vehicle has probably had about 3 oil changes in a zillion miles.
As a footnote to this thread I would like to ask others of their opinion on disabling the EGR on my Astra H 1.7 cdti (H17DTL I think). I am a bit concerned that the engine temp may increase at cruising speed and wondered if anybody has experienced any problems after doing this.
Regards, Bryan.