[Johnnyroper]

What code you getting? Is is 4862 egr to mass air plausibility by any chance?
Also what make parts have been fitted?

 

[Johnnyroper]

Egr valve is electronic on that vintage of engine, only vac is the bypass valve.

 

[Johnnyroper]

Looking at those codes I would be suspecting the inter motor maf is playing up,anything other than bmw/Bosch seems to cause issues.
Also the valve could be causing problems as one of the codes is circuit A stuck.
Ideally What you need to do is get bmw specific software connected as P codes can be misleading.

 

[Johnnyroper]

Forgive my ignorance. I don't know what this means..

The EGR valve is controlled by an electrical connection and not vacuum. The bypass for the cooler is vacuum controlled.
And yes it will be n47