Golf 2006 TDI GT BKD P0401

[Nickow09]

Hey all, I posted a while a go saying I had the P0401 emissions garage warning come on, since then I have had a tonne of work done to the car as it was cheap enough to make it worth while.
but I am still getting the same code appear.
i had a new turbo as it was whistling prety loud
new egr
new maf
exhaust taken off and check for carbon build up
egr system taken apart and all pipes blown out.
apparently there is a pipe or something which connects the egr to the exhaust? The guy I was talking to didn’t know what it was call but that apparently been replaced, shall double check with the garage owner soon.

What else can make this code come on?
at the moment the car is running perfectly, and don’t want this issue to undo what’s been fixed

any suggestions would be great.

[Rob69]

Have you run a VCDS scan on it, it could be the V157 anti shudder / Intake throttle flap failing to modulate correctly and giving you the EML. This is located in the intake air system upstream of the EGR valve.

[Nickow09]

I don’t believe the garage which did the work has the scanner needed, Is there something I can physically do or check to see if that is the problem?
if not maybe it is about time I get it looked at by someone with all the gear.

[Rob69]

Not really something you can check while driving without the gear and half an idea, you could remove the intake pipe to the throttle flap body and look in using a mirror to see if its caked up but there are plastic gears that drive the flap that are prone to stripping and you need to pull the cover off to see these.

[Crasher]

With the engine idling, disconnect the vacuum pipe to the EGR valve and see if there is an vacuum and if you can here the valve respond, suck on the capsule fitting with a piece of hose to make sure you cannot draw air through.