There are EGR settings to reduce the usage, which can smooth out idle from too much EGR usage.
However, it also can be overfueling injectors. Aging injectors tend to leak and run rich.
The more likely is to raise your injection pump's Injection Quantity (IQ) with a 'Hammer Mod'. Loosen the pump lid and move it to a higher I.Q. number. That would mean you move the pump IQ toward the passenger side, while watching the IQ numbers on your VCDS. This is done with all fans, a/c or other load on the engine turned off.
It takes a special triangle tool to loosen the front passenger side screw in the lid of the pump. The other screws are about a 20 torx bit. We don't like the tool that is sold for about $39 around the club. Instead, we use a 1/4" drive 7mm, 6-point socket and cut three of the flats 120 degrees apart, into the triangle shape with a 'christmas tree' shaped carbide cutter. Cut and test.. when it fits snugly onto the security screw, it's a good, cheap tool. You can't do it? We make them for $9 plus shipping.
Then, moving the lid toward the passenger side of the engine will make the pump's IQ rise, which lowers fuel usage.
This is our method of testing for 'optimized fueling'.
Basically, you raise the IQ until you lose performance. We run in 3rd gear, starting at 35 mph. Go to Wide Open Throttle (WOT) and when you reach 40 mph, count three seconds on a stop watch (or your Iphone), look at the speedometer.. Raise IQ incrementally until you lose MPH. Reset IQ to the previous number that preserved speed.
Questions? Feel free to call.