Need some assistance with my diagnostic - please (logs provided) :)

Hello All
I hope some people here can help me out as I like to do this myself than to leave with a garage who will probably just throw parts at it and do more guess work. Money is a little tight and I do like working on problems myself anyway.

Brief history
S3 2011, CDL Engine, DSG 6 speed with 70k miles
I got the car in August and it seem to drive ok I do not recall ever getting a management light.
Upon getting the car I replaced the DV with the newest G revision from Audi.
I had no faults to suggest anything but in the knowledge that the DV needs replaced I thought with my car having 70k miles it would be a good idea.

I booked the car in for a service in early October 2019 and had following done;
fuel filter, oil, plugs, haldex, oil filter, air filter,cam follower, oil pickup pipe.

I can't say for sure the service and my next issues relate but in late November I noticed the car going into limp mode. I used my bluetooth vagcom thing and dashcmd on the iphone and found the following errors;
Code P0172: System too rich (Bank 1) P0172
P0441 - Evaporative Emission System Incorrect Purge Flow

I hoped these both related and replaced the EVAP sensor (i bought a cheapy one on ebay) it didn't resolve the issue so I bit the bullet and bought one from Audi...It resolved the issue and I also replaced the carbon canister (got that on amazon so not genuine audi). The EVAP error (P0441) has never come back since.

I get the limp mode on a daily basis almost and appears to come sooner the harder I drive it.
The bluetooth dongle/dashcmd always displays the same fault "P0172".

I replaced the MAF, dip stick, fuel cap and PCV.

I eventually got VCDS and it looks like it is showing a different error code but kind of the same thing "too rich condition"

Address 01: Engine Labels: 06F-907-115-CDL.clb
Control Module Part Number: 8P0 907 115 AP HW: 8P0 907 115 B
Component and/or Version: 2.0l R4/4V TFSI 0010
Software Coding: 0103000C1C0F0160
Work Shop Code: WSC 14129 411 435910
1 Fault Found:

008568 - Bank 1; System Too Rich off Idle
P2178 - 002 -
Freeze Frame:
Fault Status: 01100010
Fault Priority: 2
Fault Frequency: 3
Reset counter: 255
Time Indication: 0
Date: 2020.03.01
Time: 13:40:16

Freeze Frame:
RPM: 1771 /min
Load: 47.0 %
Speed: 22.0 km/h
Temperature: 63.0°C
Temperature: 22.0°C
Absolute Pres.: 970.0 mbar
Voltage: 14.097 V


Readiness: 0000 0000


---
When I look at Group 32 and 33 with this fault logged I see;

Address 01: Engine (8P0 907 115 AP)

16:23:58 Group 032: Lambda Control (Mixture Adaptation)
5.3 % Adaptation (Idle) Bank 1 Sensor 1
-23.0 % Adaptation (Partial) Bank 1 Sensor 1



16:23:58 Group 033: Lambda Control
-2.7 % Lambda Control Bank 1 Sensor 1
1.48 V Sensor Voltage Bank 1 Sensor 1


- Obviously the -23% is the cause for the fault.

Question 1:
Why is this a different code to the bluetooth dongle I use?

Question 2:
I ran a measure on groups 32 and 33.
I reset all error codes to return fuel trims to 0.
On group 32 it's 0% and 0%
On Idle group 33 - short term fuel trim flucuates between -2% and 2%.
From what I understand that's perfect?
My research suggests that a VAC leak is only evident on idle and would show up on this idle test. I seen the effect of the dip stick test on youtube but it seems my car has no such vac leak..

Question 3:
When I rev the car in nuetral whilst meansuring groups 32 and 33 I noticed that short term fuel (in group 33) jumps upto -15%. Is this normal behaviour ?

Question 4:
I do not know if my car is remapped but I ran a quick test, I used 3 gear and set box to manual.
I get MAF readings like;
Group C: 002
Engine Speed Engine Load Injection Timing Mass Air Flow
TIME (G28) Sensor (G70)
STAMP /min % ms g/s
17.97 4320 146.6 4.08 134.31
18.33 4720 143.6 4.08 143.47
18.69 5120 139.1 4.08 150.11
19.03 5480 142.1 4.34 165.22
19.41 5840 145.1 4.34 181.47
19.77 6200 145.9 4.34 196.58
20.11 6560 152.6 4.59 217.67
20.49 5080 174.4 4.34 212.11
20.85 5160 191.7 6.12 221.47
21.24 5440 191.7 6.12 230.22
21.62 5680 191.7 5.87 237.33
21.96 5920 191 5.61 240
22.33 6160 184.2 5.61 241.31
22.69 6360 178.9 5.36 243.67
23.02 6600 173.7 5.36 244
23.39 5880 172.9 4.34 219.22
23.74 5080 176.7 5.61 194.53
24.11 5080 15.8 0.51 10.81


I believe if you take highest figure and devide by 0.8 it gives rough estimate of BHP? so 244/0.8 = 305bhp ? That would indicate a remap?


Question 5
Does this look like a boost leak or is it normal boost?

Group C: 115
Engine Speed Engine Load Boost Pressure Boost Pressure
TIME (G28) (specified) (actual)
STAMP /min % mbar mbar
43.52 1600 31.6 500 990
43.87 1680 27.8 440 990
47.97 1960 65.4 1040 1000
48.08 2040 69.2 1060 1010
48.19 2080 74.4 1090 1020
48.32 2120 78.9 1140 1040
48.44 2200 83.5 1290 1060
48.55 2240 87.2 1520 1080
48.66 2240 93.2 1590 1090
48.77 1920 104.5 1450 1120
48.89 1960 108.3 1440 1150
49 1920 111.3 1430 1170
49.12 1920 113.5 1430 1190
49.22 1920 115 1420 1190
49.33 1960 115.8 1450 1210
49.46 2000 118 1460 1220
49.56 2040 119.5 1510 1230
49.68 2120 121.8 1550 1250
49.78 2160 124.8 1590 1260
49.91 2200 127.1 1650 1290
50.05 2280 131.6 1660 1320
50.18 2320 133.8 1650 1350
50.29 2400 136.1 1620 1370
50.41 2440 139.8 1600 1400
50.54 2480 133.1 1480 1430
50.67 2600 118.8 1220 1460
50.79 2600 103 1140 1480
50.91 2680 91.7 1000 1410



164.49 2040 109.8 1730 1150
164.6 2160 112.8 2000 1170
164.73 2360 115.8 2120 1210
164.85 2600 118.8 2220 1250
164.99 2920 125.6 2230 1320
165.1 3040 135.3 2230 1380
165.23 3360 147.4 2240 1490
165.35 3600 163.9 2230 1630
165.48 3800 181.2 2210 1790
165.6 4000 191.7 2230 1960
165.72 4280 191.7 2230 2020
165.82 4520 191.7 2230 2040
165.93 4560 191.7 2240 2090
166.05 4760 191.7 2250 2120
166.2 4920 191.7 2250 2120
166.32 5080 191.7 2260 2120
166.43 5240 191.7 2260 2100
166.54 5400 191.7 2260 2080
166.66 5520 167.7 1450 1920
166.8 5600 118.8 870 1790
166.91 5640 60.9 620 1790
167.03 5640 31.6 490 1420
167.15 5680 23.3 360 1330



Question 6
From all of the above what would you suggest? The car smells like it's running rich, the MPG isn't great i'm getting roughly 30 miles to £10 of fuel around the city... When I reset codes the car pulls like an absolute train - it's very quick! but then this limp code ruins everything! If I had a boost leak I would expect lesser performance.. Does it sound like an O2 sensor?

I have a warranty for "non wear and tear" parts only...

Please help a brother out i'm so baffled by this fault

Anyone?

I can find nothing online about p2178... I don't understand how the short term fuel adjustment goes to high - % when I use throttle.
If it was a boost leak it wouldn't be apparent while i'm rev'ing in N as in N gear the turbo doesn't spool, right?
I confirm that also by recording the requested and actual boost and it remains at baseline.

Sorry Samuel I was just a bit frustrated with this fault as usually you find so much information on the internet or a forum search..
However every search i've found people have it and never post what actually fixed this error - it seems quite uncommon too.

I learnt a lot about fuel trims over the last couple of weeks - although still no expert it's nice to know how to diagnose certain things using that method.
I checked te fuel pump duty cycle and it seems to be normal on idle (around 40% if i remember correctly).

I'm starting to think maybe it's a leak after the MAF - where would be a good place to look for that? The pipe that connects to the turbo?
On the bit you posted it mentions
"When found in the NAR 2.0T (BPY) check RVUTB: 01-09-03 or 2018919 for updated Crankcase Breather Valve"

I assume this isn't related to my engine?

Seems leak in the turbo outlet pipe that connects to the charge pipe from the turbo.

Where can I get a replacement for this? is it easy enough to DIY, or do you need to access it from under the car?

I know it comes as muffler delete but i don't care enough to muffler delete if all i get is improved sound.

Thanks so much for those links!
Do you have a part number for the green o'ring?

Also is this easy to do DIY? Is it all within reach from top of the engine or am I going to need to get the car up on the ramps?
I searched so much on yourtube for s3 8p turbo outlet and see no videos with this and all the turbo muffler delete stuff is for entirely different engines..

Hi Samuel

Forgive me if i'm wrong but was the MK6 golf not the same as the s3 8p face lift?

Thanks for that part number

Hello, just to update this I found the issue.
Unfortuantely I ruled out a boost leak by during a vcds test of requested + actual boost pressure.
Because I was getting the requested I *ASSUMED* it wasn't possible to have a boost leak...

As this issue became worse under full load I should have known it must have been some boost leak. Weirdly I never heard anything...

There you have it, if you get this fault it's most likely you have a boost leak...

I'm no master mechanic but I was able to replace this pipe, the charge pipe and demuffler kit (i didn't want demuffler kit but it's the only way to buy this part after market) in the space of 3 hours using jack stands.

Very happy to have the car performing as normal again. Thanks for your input guys!