My recently acquired diesel Sandero threw up code P049B, (egr valve low flow). I removed the egr valve, it was well clogged up with sticky black goo. I also removed the pipe that feeds exhaust gas to the egr valve, that was clean. All the orifices where the pipe and valve fit were cleaned out.

All reassembled and code cleared. 50 mile later P049B is back. So is there something else I should be looking at, or is it replace the egr time?

Thanks in advance Jon.