Leak in Air Intake System P2279

[BlackMajj]

Sorry in advance for wall of text but I'd rather give too much info in hope that someone out there recognizes the symptoms...

I have an Audi A6 2.0TDI from 2008 that has P2279 Leak in Air Intake System.
I am not skilled at anything to do with cars but I try my best at doing things myself and noticed when trying to find the issue that the hose that goes out of the top right of engine to the intercooler was a bit loose.
Removed it and found the gasket had broken.
Ordered a new one and slapped it on and now the tube is snug but the issue is still there.

Symptoms:
Whenever I start the car the glowplug light stays off and engine works as normal.
When I start driving, as soon as the engine has to work a bit more (I.E going up small incline) it goes into limp mode and glowplug starts blinking.
If I need to go up a long incline on a hill I can restart the car and then drive it in manual keeping the RPM >2000 and it will function but as soon as the RPM goes too low, limp mode comes on.
It does not seem to go into limp mode even with heavy load on incline on low RPM in 1st and 2nd gear. Guess the torque is high enough then?

I have noticed since this issue arose that when my engine works harder (going up small incline or high gear/low rpm flat ground trying to accelerate) my RPM meter does a quick jerk upward every 2s as long as RPM is <1900 (even in limp mode). When RPM is above that level it does not jerk at all.
The "every-2-second-jerk" can be felt too so it's not just issue with RPM reading.

From Vagcom:

                Address 01: Engine       Labels: REDIR FAIL!
Control Module Part Number: 03G 906 016 MF    HW: 03G 906 016 MF
  Component and/or Version: R4 2,0L EDC G000CG  1142
           Software Coding: 0000076
            Work Shop Code: WSC 66565 257 00032
                      VCID: 73FBFAC38BB5DD9A12E2211-8026
1 Fault Found:

008825 - Leak in Air Intake System
               P2279 - 000 -  - MIL ON
             Freeze Frame:
                    Fault Status: 11100000
                    Fault Priority: 1
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 238814 km
                    Time Indication: 0
                    Date: 2023.11.07
                    Time: 14:32:47

             Freeze Frame:
                    RPM: 1344 /min
                    Speed: 39.0 km/h
                    Load: 24.3 %
                    Voltage: 13.76 V
                    Bin. Bits: 00101000
                    Torque: 178.1 Nm
                    Temperature: 79.2 C

I also have intermittent fault on the P3103 Motor for Intake Manifold Flap (V157) but that one should not be causing this issue since the flap has been intermittent for two years and the other issue is new. (and since it only affects the engine shaking when I turn it off I've not fixed it yet)

Anyone out there know where I should start to look for the issue?
I tried looking at youtube vids about the P2279 but all the things they look at I can't seem to find on my engine. At least they are not where they are shown on their engines. 😞

TL;DR: A6 2008 2.0TDI with P2279 Leak - I've replaced a gasket on hose going to intercooler but still air leak. Enging RPM jerks every 2 second when heavy load. Goes into limp-mode if rpm <2000 when heavy load.

[Steve Q]

It could be an issue with the hose itself letting additional air in where it joins. Under load the additional air could be being drawn through due to the pipe not being as tight due to age.