a7 bitdi misfire and juddering

[Buthoan]

Hello!,I'm own A7 bitdi 3.0 313 hp model,I have issue and unfortunately from 6 months I can't repair it.Car issue is engine can be both hot or cold doesn't matter between 1000-1400 rpm during cruising car is juddering like a misfire.I bring car to  service they put in diagnostic there is no fault on diagnostic service told that issue can to be from EGR,inlet manifold.First they removed intake hose and sprayed Egr&manifold cleaner spray during car was on 2000 rpm and then they removed egr,and inlet manifold they cleaned and changed seals of egr.So after almost issue fixed it was again juddering and misfire on low rpm during cruising but was more better not was like before misfire so passed 3 weeks I drove car long distance around 1200 km unfortunately on road Truck crashed and stuck on road so That's why traffic locked and I drove car about 1 hour and half with 20 km/h speed and after car again started judder and misfire as like before  between 1000-1400 rpm.So is there any body who had same issue ? What was issue? Unfortunately we can't found issue on diagnostic

[Steve Q]

What else has been changed? 

Might be worth changing the spark plugs and ht leads to start off with as well as the injectors. 

[Buthoan]

Also 6 injectors has replaced in official Audi service before 52.000 km from pre-owner,I also changed again seals of injectors but it wasn't help for issue.About glow spark plugs Sir I know diesel engines need glow spark plug only for during starting engine for heating diesel I don't think so it's about glow spark plugs because I have this issue not matter engine cold or hot.

I'm suspecting from just one thing which reason can to be issue from pre-owner The Insruance company has placed to into car one like obd and chip key and sometimes car not starting if I will not push button in this chip key,This chip key cuts car electricity sometimes and just on Diagnostic has this Fault code(Starter Relay P3088 00 [101] - Electrical Malfunction Not Confirmed - Tested Since Memory Clear) no more fault code.Is it possible that it can causing from it

[Steve Q]

Apologies, I'd misread being a diesel could it be a turbo, or cam sensor 

[Buthoan]

Yes Sir reason can to be Turbo or hose of Turbo can to be damaged and because of this hose can lost air.By the way When I steep on throttle full on when car gear on N rpm increasing until maximum 2500 and no more than 2500 and juddering also there