2007 A4 B7 1.9 TDI Avant - Rough engine, uneven performance

[intech]

Car: Audi A4 Avant 2007 (8EC, B7) 1.9 TDI (Engine codes: BKE, BRB)
"Euro car" and located in Norway.

Summary:
Struggling with this one and really hope someone can shed some light or provide some ideas/suggestions.
For about 1,5 years I have had problems with poor/uneven performance and engine seems a bit too rough.
EGR was replaced after full engine stop. And this helped.. but seems to me EGR is more of a symptom/victim, rather than the ultimate cause.
Symptoms:
- Engine running seems a bit rough, uneven and sometimes poor performance (lower end rpm/speeds particularly). Can shoot off and at other times be more sluggish. (Less pronounced after EGR replace)
- Engine is a bit loud and sounds 'untypical' (hollow/muffled)(?).
...Otherwise starts quite easily cold/warm.

Recent service/parts changes:
Oil (Castrol EDGE Titanium FST 5W-30 LL) and oil/air/diesel filters. Also replaced EGR, MAF sensor.

Out of curiosity and obviously self interest. I got cable/software(vcds) to read diagnostics and do some logging (RPM,TPS,MAF,MAP).
Interestingly, I noticed something that seems off to me from what I can understand.. TPS values appear choppy/abnormal.. Or is this normal?
Fig.1 below is graph of TPS compared to RPM. (I have more readings, but trying to keep it short and add more if it will be helpfull)
This is a normal short/mixed trip I did recently, start to finish, with idle at the end.
tps-rpm_10032017.jpg

Any suggestions and/or tips are very welcome! Other metrics I should include or diagnostic procedures to perform?

Long story:
I have tried to complain to dealers and back alley shops about the condition of this car for a good while. Always got the "it's probably nothing" or random suggestions..

Before EGR replace, symptoms was:
- Rough running, uneven performance, dead pedal.
- Occasional hard stuttering at low speeds.
- Particularly at lower end of rpm/speed.
- Occasional start problems (warm start)

It got progressively worse until it ultimately led to a full engine stop, engine warning light etc. And 'road rescue' to the nearest dealer.

I managed to print fault codes before auto rescue arrived..
2 Faults found:
###
000257 - Mass Air Flow Sensor (G70)
P0101 - 000 - Implausible Signal

000305 - Oxygen (Lambda) Sensor B1 S1
P0131 - 000 - Signal too Low - Intermittent
###

Local dealer happily announced they have found the cause. EGR valve was stuck in open position and adviced to replace it. I accepted and they signed the car off and "problem solved".

Changing the EGR helped and hard stuttering seems completely gone. But sadly I noticed pretty much immediatly that it still did not feel right. Seems too rough and struggle/more than normal. And sure enough I noticed the occasional uneven/poor performance and "dead pedal". Engine also is a tad loud/untypical.

I returned to the dealer about the issue and mechanic there agreed regarding the sound and general running. After about an hour inspection (including cam shaft/valve inspection) he couldn't conclude anything, but suspected MAF because of the MAF fault code (from when engine stalled because of EGR).
I was doubtfull about this. And given the EGR issue, those fault codes seems reasonable and related to that incidence.. but I still replaced the MAF and cleared fault codes. But this didn't change much if anything.
Feel I have tried all options for my area/situationn and at a loss now.. really hope someone shed some light on this...!

Sorry if this post is a bit long..

[Scott K]

Any chance it is the intake manifold flap? Although it should give you a fault code if it is sticking. Have you checked all your vacuum hoses?
If you have access to VCDS and post the scan it will help.

[intech]

I am starting to wonder if it could be related to Throttle Body/Intake Manifold Flap.. Readings from Throttle Position Sensor look odd/abnormal or no?
Really dissapointed about the local Audi dealer if that really is the case.. as they had a chance to look at this.
Any other related valve or sensor that could cause the symptoms/TPS readings I am seeing (if they indeed are abnormal)

Only fault codes I ever had was when the EGR valve godt stuck open and engine stopped.. (2.5 months ago) I'll paste the full report in the next post..
I have tried to read again recently (after replacing MAF etc) and I get "No fault codes found" (engine module)

[intech]

Fault codes readings on engine stall and EGR valve stuck open.. (30 December 2016)

Control Module Part Number: 03G 906 016 GD
HW: 03G 906 016 GD
Component and/or Version: R4 1,9L EDC G000SG 8957
Software Coding: 0000071
Work Shop Code: WSC 06325 000 00000
VCID: 6BD25F834A96576698-803E


000257 - Mass Air Flow Sensor (G70)
P0101 - 000 - Implausible Signal
Freeze Frame:
Fault Status: 01110000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 169452 km
Time Indication: 0


Freeze Frame:
RPM: 1260 /min
Speed: 30.0 km/h
Temperature: 11.7°C
Absolute Pres.: 1050.6 mbar
Mass Flow: 12.80 g/s
(no units): 1.42
Temperature: 59.4°C

000305 - Oxygen (Lambda) Sensor B1 S1
P0131 - 000 - Signal too Low - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 0
Fault Frequency: 14
Reset counter: 255
Mileage: 169460 km
Time Indication: 0


Freeze Frame:
RPM: 1323 /min
Speed: 19.0 km/h
Load: 45.1 %
Mass Air / Rev.: 280.0 mg/str
(no units): 0.70
(no units): 0.0

[arman123]

Did you use a genuine audi MAF for replacement

[intech]

Did you use a genuine audi MAF for replacement

I bought this one to be specific: AUDI VW SKODA SEAT MASS AIR FLOW METER SENSOR 0281002461 074906461B | eBay
No good? I was doubting maf related problems as it sounds/feels same before/after changing it and given the nature of the problem.

[arman123]

What's your engine code? BKE or BRB

[rowdy-999]

Only replace the MAF with a Bosch unit (OEM), not cheapo.

[intech]

What's your engine code? BKE or BRB

Not 100% sure about the engine code, tried to ask dealer also without luck. Think it's BRB. What differences are there and is there an easy way to check to be sure?

Only replace the MAF with a Bosch unit (OEM), not cheapo.

Ok. I will consider getting the bosch one.. especially if things get worse
But I honestly think something else is going on.


About the vacuum hoses.. is that an easy thing to inspect and something my audi dealer would have checked already? Given that they had my car for diagnostics/inspection..

[arman123]

Get a genuine maf from dealer also engine code can be found on cambelt cover front on engine