Audi A3 diesel Limp Mode glow tube flashing

[Tezza789]

I have the following issue on my sons car which is a 2012 Audi A3 8P diesel. 
It has recently started dropping into limp mode. 

I used a basic Autel error code tool which said error P046C which i believe is EGR issue. A big and costly job to changeout an EGR valve on this model. Just want to make sure it is nothing else. I did spray in some Wynnes EGR spray and the car ran fine for about 30 mins and then when i accelerated above 3000 rpm the glow tube light came on with the dreaded limp mode. Any thoughts welcome. Car is 2012 with around 60k miles on clock.It does reset by stopping and restarting the engine.

I dont understand the reason to go to limp mode if the EGR is an emissions issue. It seems more dangerous to be in limp mode on a motorway especially with no hard shoulder.

 

[cliffcoggin]

2 hours ago, Tezza789 said:

I dont understand the reason to go to limp mode if the EGR is an emissions issue. It seems more dangerous to be in limp mode on a motorway especially with no hard shoulder.

If it did not go into limp mode people would ignore the problem and continue belching nasty emissions into the atmosphere.