Did he replace the valve and solenoid? Or just the valve? (I've known after-market valve & solenoid combinations not open sufficiently and MAF detects too much air-flow vs EGR duty, logging this fault code). Also, if the EGR has been blanked, it will log a DTC too.
Also, check the clutch switch. Doesn't always log a fault code, but does give odd driveabilty issues
as it thinks you're coasting.....

The info I have is based on a 2.0CRDi Kia Sportage, but I'm pretty sure they're the same.
These are prone to blocking up the EGR pipework and ports, so might be worth a strip out and clean up operation before anything else.

If he's had the MAF off, make sure the plug's on the right way around (but I think that logs an IAT DTC too).
Also, check he hasn't knocked the Turbo vacuum pipe off.


Live data, is different dependent on if it's a variable geometry Turbo (electric EGR):
MAF should read around 410mg/st +-50mg/st at idle with 5% EGR duty
Or 360mg/st +-50 at 45% EGR duty

Or waste gate turbo (pretty sure these have a vac operated EGR) :
MAF should read 450-550 mg/st at 5% EGR duty
or 300-400 mg/st at 40% EGR duty

There is an option to reset MAF values in the ECM, if you can do it, it may be worth a try.