Chassis 202.028 has a TSB up-grade for the EGR valve due to sticking.
They also have a flow blockage problem that you can find in the Archieves. [ DIY article by S.B ]
The blockage is more apt to bring up the CE lamp as it is a constant failure , whereas the sticking egr will sometimes not CE indicate cuz of it's intermittent condition. [ thus not having successive faults needed for ECU recognition]