Ocasional emissions light?

[avatarz]

So my A3 2007 2.0tdi quattro has suddenly started displaying the emissions control system light..

This happened last friday.. and after a VCDS scan it shows:

16785 - EGR System
P0401 - 000 - Insufficient Flow

No loss of power, infact i would say its perfectly fine.. i cleared this and the light went out - drove a full week (roughly 150miles) and its just triggered a light again.. my trips are fairly long (motorway too)

Any ideas?

 

[Retroman]

Suggests some carbon clogging in the EGR system and/or sticking EGR valve. If it was me, I would first try some EGR cleaner to see if the situation could be improved without getting my hands dirty

 

[avatarz]

thanks - so i cleaned all around the valve today.. i have cheated slightly and sorry to say i ran some cleaner though it (took the turbo pipe off)

Note: when it heats up a bit i think its probably worth me taking this off and cleaning it/regasketing it, but as its minus temps at the moment the above is plan b

I ran it with pipe pushed back on and it kicked a ton of black out the back (which i assume is good) that the cleaner did something, did have a bit of an issue getting that turbo pipe back on! man that clip etc is a PITA

Cleared light/code and then took it for a "sprinted drive" to clean it- so far.. lights not come back

so the real test is after a full week of driving it!

My only notice is that it does seem to seep a bit out the top of the valve, i have heard this is fairly normal but im wondering if the gaskets do need doing as well 130K car - so i assume its not been done!