Been out in my cupra today. On the way home a warning light came on. Checked the manual and its the diagnosis / excess pollution light came. 
Got home switched off the engine turned the engine back on, light still on. In the manual it states that it should go off after a few seconds. Mines staying on.
Anybody knows what it could be?
Would hitting a rather large pot hole cause this problem?

Got home switched off the engine turned the engine back on, light still on. In the manual it states that it should go off after a few seconds. Mines staying on.
Anybody knows what it could be?

Would hitting a rather large pot hole cause this problem?