Hello everyone!

I assume someone here might have experience about my problem. My car is Audi A6, 2010, 2,0 TDI, 100kW.
My glow plug light started to blink about a month ago. I got rid of the light with Autocom (fault code was P040300, Exhaust gas recirculation circuit, intermittently). It stayed away for about three weeks.
It came back last week and I can’t get it off anymore. Also “check engine” -light appeared. Same fault code as before.
I cleaned the EGR-valve last weekend in hope that it would fix the problem. As You can guess it didn’t.
I think the EGR-valve has been cleaned before because it was in rather good condition in relation to the driven kilometers (~290 000). There were exhaust residue also in the EGR-control motor box.

I read the fault codes with Ross-Tech and got this:
1 Fault Found:
4892 - EGR Valve (N18)
P0403 00 [172] - Malfunction
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 3
Mileage: 289551 km
Date: 2016.05.13
Time: 18:47:05

Readiness: 1 1 0 0 1

What is Your opinion, will the problem be solved by changing the EGR-valve or is it more complicated problem?
Thank You in advance!