When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
This is just a though but i have changed 2 EGR valves for that reason.
The spring on the back side of the diafram was weak and the valve would open to far on heavy accelleration and hang up ther until you let off on the throttle.