Fighting with P2177 (running lean)

[Finder]

I've been fighting this code for about 5 weeks, threw new parts at it (MAF, front O2 sensor, G247 fuel rail sensor) and did a smoke test through the intake (no leaks). New valve cover and fuel filter were replaced earlier in December. Cam follower was replaced in October.
I run a K04 with Unitronic tune, intake, downpipe and intercooler, Autotech HPFP, Eurojet DV reroute, IE PCV block-off, Forge DV (swapped it to GFB DV+ now but code came back).

Using VCDS I see Group 32, adaptation idle -0.7% and adaptation partial 21.5%

I've done some logging too:

RPM Timing Angle BTDC
2120 21
2160 21
2160 21
2200 21
2200 20.3
2240 20.3
2280 13.5
2400 6
2480 2.3
2600 -3.8
2720 -8.3
2840 -9
3040 -8.3
3240 -8.3
3360 -6.8
3560 -6
3720 -5.3
3920 -5.3
4080 -5.3
4240 -4.5
4400 -4.5
4600 -3.8
4760 -3.8
4840 -3.8
5040 -3.8
5240 -3
5320 -3
5440 -3
5560 -3
5680 -2.3
5800 -2.3
5920 -1.5
6040 -1.5

Fuel
Rail Pressure (specified) Rail Pressure (actual)
72.3 72.3
73 73
74.2 74.2
74.9 74.2
75.5 75.5
78.1 76.2
87 90.9
95.4 97.3
105 103
108.8 108.8
109.4 109.4
109.4 106.2
109.4 107.5
110.7 108.2
112 110.7
113.9 112.6
115.2 113.9
115.8 117.8
117.1 116.5
117.8 116.5
118.4 118.4
119.7 119.7
122.2 124.2
125.4 124.8
128.6 124.8
129.3 125.4
129.3 128
129.9 131.2
129.9 129.9
129.9 130.6
129.9 131.8
129.9 130.6
129.9 130.6

RPM Group 106 - Field 1 Electric Fuel - Pump 1/2
2000 51.8
2080 52.9
2200 54.1
2320 56.1
2480 58
2640 60.4
2840 62.4
3040 64.7
3320 67.5
3560 69.4
3840 71.4
4040 71.4
4280 73.3
4600 75.7
4720 76.5
4880 76.5
5080 76.5
5240 77.6
5440 78.8
5600 80


RPM MAF
2120 14.17
2160 14.33
2160 14.78
2200 14.81
2200 15.22
2240 30.31
2280 50.36
2400 59.56
2480 75
2600 99.25
2720 126.14
2840 128.89
3040 124.64
3240 119.14
3360 144.44
3560 152.08
3720 167.19
3920 166.53
4080 184.5
4240 188.17
4400 195.75
4600 202.19
4760 203.31
4840 205.19
5040 208.75
5240 213.78
5320 218.56
5440 218.33
5560 221.11
5680 227.56
5800 230.14
5920 230.39
6040 233.36

RPM Boost specified Boost actual N75 (%)
2440 2110 1550 74.5
2560 2120 1950 74.5
2680 2120 2340 74.5
2880 2130 2500 74.5
3040 2120 2400 58.8
3240 2120 2400 59.6
3480 2100 2430 56.9
3680 2070 2410 56.1
3880 2040 2400 56.1
4080 2020 2370 56.1
4240 2010 2350 55.7
4440 1990 2290 54.1
4640 1960 2280 53.7
4880 1940 2270 51.4
5000 1920 2220 51.4
5200 1910 2170 50.2
5360 1910 2150 47.1
5480 1900 2120 46.7
5640 1890 2090 45.5
5760 1880 2060 45.5


Based on all this it seems my problem is with timing angle between 2000-2500rpm. I don't see any LPFP or HPFP issues in the logs myself and like I said above I've replaced MAF, O2, G247 and checked for intake leaks.
Not sure what to try next...

 

[clockwise33]

Confirm that you are running the correct tune for a K04. Your requested boost looks more like a K03 tune.

 

[Finder]

You think so? I've been running this file for 3 years now. The car was fine until a few weeks ago when it started running lean.

 

[clockwise33]

Has the tune always asked for so little boost? Do you have logs from when it was running well?

You have S3 injectors, correct? One may be clogged or dying. See if 1 cylinder is worse than the others by looking at your plugs and logging cylinder specific timing correction.

 

[Finder]

No. I think it's lower because of the condition.
Here's rpm, requested and actual boost immediately after I clear the engine codes (reset fuel trims) and log a WOT run in 3rd gear:

RPM REQ ACT
2480 2410 1180
2640 2490 1440
2800 2480 1750
3040 2480 2260
3360 2480 2550
3760 2480 2550
4040 2460 2550
4600 2420 2530
4640 2410 2500
4760 2380 2470
5000 2350 2440
5280 2330 2400
5520 2310 2330
5720 2300 2280
5960 2280 2230
6120 2250 2190
6400 2220 2160
6640 2190 2150

The car pulls strong after I clear the codes, but once the fuel trims settle it becomes lazy and eventually the CEL shows up for P2177.

 

[Finder]

I've logged throttle valve angle and timing retardation per cylinder last week.

RPM THR CYL1 CYL2 CYL3 CYL4
2120 10.2 -12 -12 -12 -12
2160 10.2 -12 -12 -12 -12
2160 10.6 -12 -12 -12 -12
2200 10.6 -12 -12 -12 -12
2200 11 -12 -12 -12 -12
2240 11 -12 -12 -12 -12
2280 30.2 -12 -12 -12 -12
2400 99.2 -12 -12 -12 -12
2480 99.6 -12 -12 -12 -12
2600 99.6 -12 -12 -12 -12
2720 99.6 -12 -12 -12 -12
2840 99.6 -12 -12 -12 -12
3040 96.9 -12 -12 -12 -12
3240 96.1 -12 -12 -12 -12
3360 96.9 -12 -12 -12 -12
3560 97.3 -12 -12 -12 -12
3720 97.3 -12 -12 -12 -12
3920 96.9 -12 -12 -12 -12
4080 96.5 -12 -12 -12 -12
4240 96.1 -12 -12 -12 -12
4400 96.1 -12 -12 -12 -12
4600 96.5 -12 -12 -12 -12
4760 96.5 -12 -12 -12 -12
4840 96.9 -12 -12 -12 -12
5040 96.5 -12 -12 -12 -12
5240 96.5 -12 -12 -12 -12
5320 96.5 -12 -12 -12 -12
5440 96.9 -12 -12 -12 -12
5560 96.9 -12 -12 -12 -12
5680 96.9 -12 -12 -12 -12
5800 96.9 -12 -12 -12 -12
5920 96.9 -12 -12 -12 -12
6040 96.9 -12 -12 -12 -12

And I don't get any misfires.

 

[5aprilc]

Shouldn't you be doing your logs in 4th gear?

 

[clockwise33]

I would start by pulling the spark plugs and seeing if one is much lighter than the others, which would point towards injector. Besides that, it has to be a large air leak. Try spraying brake cleaner around any possible leak points as the engine idles. You will hear the idle jump when you spray the area that is leaking vacuum. Include the front and back PCV connections, throttle body, manfold, evap and n75 connections to turbo inlet, DV reroute etc.

 

[Finder]

Shouldn't you be doing your logs in 4th gear?

Normally yes but they can be done in 3rd.
In 4th I'll end up driving way too fast as I get close to the RPM limit. Gotta stay safe.

I would start by pulling the spark plugs and seeing if one is much lighter than the others, which would point towards injector. Besides that, it has to be a large air leak. Try spraying brake cleaner around any possible leak points as the engine idles. You will hear the idle jump when you spray the area that is leaking vacuum. Include the front and back PCV connections, throttle body, manfold, evap and n75 connections to turbo inlet, DV reroute etc.

I will pull the sparks as it's an easy job but I doubt that's where the problem is. I use injector cleaner at least 2 times a year as a preventive measure for this.
As for leaks I already ran smoke through the intake tube and couldn't find any leaks anywhere.

I think I will test my exhaust for leaks next.

 

[larcic]

clean your maf sensor specially if you have an oiled filter(even though your readings seem ok but could be a little higher). Also could be an o2 sensor but less likely. have you logged AFR to see if you are actually running lean? I was at 15-17% on the partial and passed a leak test as well and my AFR was still fine(I got a lean code once or twice). I took off my intake completely to check the coupler and change the oiled filter for a dry aem filter and now I'm sitting at 7.0% my car drives way better. I had already replaced the o2 and maf but that didnt solve my issue. good luck with this, I spent alot more time and $ finding the issue than I would like.

 

[Finder]

I've logged Group 32 before:

RPM Idle Partial
1840 -0.5 20.7
1840 -0.5 20.7
1840 -0.5 20.7
1840 -0.5 20.7
1840 -0.5 20.7
1840 -0.5 20.7
1840 -0.5 21.1
1880 -0.5 21.1
1960 -0.5 21.1
1960 -0.5 21.1
2040 -0.5 21.1
2080 -0.5 21.1
2160 -0.5 21.1
2280 -0.5 21.1
2360 -0.5 21.1
2440 -0.5 21.1
2520 -0.5 21.1
2600 -0.5 21.1
2760 -0.5 21.1
2840 -0.5 21.1
3000 -0.5 21.1
3080 -0.5 21.1
3240 -0.5 21.1
3360 -0.5 21.1
3560 -0.5 21.1
3680 -0.5 21.1
3800 -0.5 21.1
3920 -0.5 21.1
4040 -0.5 21.1
4200 -0.5 21.1
4320 -0.5 21.1
4440 -0.5 21.1
4560 -0.5 21.1
4680 -0.5 21.1
4800 -0.5 21.1
4920 -0.5 21.1
5000 -0.5 21.1
5120 -0.5 21.1
5200 -0.5 21.1
5320 -0.5 21.1
5440 -0.5 21.1
5520 -0.5 21.1
5600 -0.5 21.1
5720 -0.5 21.1
5800 -0.5 21.1
5920 -0.5 21.1


No oiled filter and I've cleaned the MAF several times but ended up buying a new one 2 weeks ago just to rule it out. And I replaced the oxygen sensor last week.
Ran another smoke leak test and high air pressure test through the intake last night and I still couldn't find anything.
Also smoked the exhaust and found no leak but I will redo this test without smoke and more air pressure once I figure out what can I use to plug my exhaust properly.
So far no leaks though and I don't know what else to try

 

[larcic]

group 32 is fuel trims(adaptations) not afr I'm not sure what group is afr since I just use torque app you should see 14.7 air to fuel ratio while cruising (maintained speed) and under WOT it should drop to 11.something by redline.

 

[larcic]

i think its group 31 but not sure

 

[larcic]

Channel 31: Lambda Reading or A/F Ratio

This value is particularly important to be viewed and interpreted only when the car is under full throttle input as lifting up on the throttle will result in funky numbers. Take your log in third gear (or higher if your local authorities will allow) from 2500rpm or so until redline. The values you will see are: 1 = 14.7:1 ratio, .85 = 12.5:1 ratio, .75 = 11:1 ratio. As you have probably figured, simply multiply the lambda value by 14.7 to obtain the ratio. A car that runs 14:1 (lambda value of about .95) all the way up to redline on increased boost is running a bit lean. Conversely, a car that is running 10:1 (lambda value of about .70) from idle to redline is running a bit rich. Remember that lean is your ultimate enemy. Running too lean for too long will spell disaster for the motor. Ideally you would like to see the A/F pass linearly from the factory 14.7:1 at idle towards 13:1 in the mid rpms (3500rpm or so) to at least 12:1 at redline (NOTE: New FSI platforms are running approximately 10.5:1 at WOT). This would show a car that is getting good fuel mileage under easy driving, but richens up nicely as you wind it out under full throttle to redline. This would make you feel at ease driving the car under high load conditions at high speeds (freeway cruising at 120mph) or using the car for frequent track days.


Example of manifold injection performance tuned a/f ratio readings: (NOTE: New FSI will request richer mixtures than this such as Lambda = .75 up top):

RPM Lambda
2500 .99
2750 .95
3000 .95
3250 .95
3500 .90
3750 .90
4000 .90
4250 .85
4500 .85
4750 .85
5000 .85
5250 .85
5500 .85
5750 .85
6000 .80
6250 .80
6500 .80
6750 .80

If this looks fine I suggest removing your intake(completely) and making sure everything is nice and tight specially post maf (coupler)

 

[Finder]

I have Group 31 log also:

RPM Throttle valve angle Lambda (actual) Lambda (specified)
2120 10.2 1.01 1
2160 10.2 0.97 1
2160 10.6 0.98 1
2200 10.6 1.02 1
2200 11 0.97 1
2240 11 0.98 1
2280 30.2 0.95 1
2400 99.2 0.94 0.93
2480 99.6 0.92 0.91
2600 99.6 0.88 0.91
2720 99.6 0.87 0.89
2840 99.6 0.88 0.88
3040 96.9 0.93 0.88
3240 96.1 0.84 0.86
3360 96.9 0.83 0.84
3560 97.3 0.83 0.84
3720 97.3 0.82 0.84
3920 96.9 0.83 0.84
4080 96.5 0.83 0.84
4240 96.1 0.83 0.84
4400 96.1 0.84 0.84
4600 96.5 0.83 0.84
4760 96.5 0.81 0.84
4840 96.9 0.83 0.84
5040 96.5 0.83 0.84
5240 96.5 0.82 0.84
5320 96.5 0.82 0.84
5440 96.9 0.83 0.84
5560 96.9 0.82 0.84
5680 96.9 0.8 0.83
5800 96.9 0.81 0.83
5920 96.9 0.81 0.83
6040 96.9 0.81 0.83

I removed the intake last night and checked the coupler to the turbo.