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..