Shane,
My air flow readings seem good and there's no noticeable lack of performance. However, I might see if I can borrow an AFM to try.

Having done some digging, it appears that this ecu doesn't have the hardware to utilise an egr valve with electronic feedback so that should rule out a configuration fault.

It's just one of those jobs where the customer has paid a bill so you're fixing for free which takes the edge off our enthusiasm!

Car's back in next week so will you all posted.

And Mark, being a smartass is of no use at all