Kangarooing when accelerating pd170

[pato]

My leon fr mk2 pd170 is running rough lately and sounds noisier than usual,it occasionally sounds like the exhaust is blowing but then the noise just stops in a instant and sounds normal again,the car has been mapped about 5 years ago (not sure by who)I've owned it for 4 years with no problems (had injectors replaced about 1year ago with the recall).
I've had the car into an independent for a check over, they couldn't find any faults logged and they tell me the car hasn't done a dpf regen they are suggesting it may be the turbo?? Apparently there is a part that's normally separate that fails for about £40 but on mine it's part of turbo aprox £1000,I'm concerned at spending that much with no specific fault code to work with,any ideas? Also lately the car seems to kangaroo quite a bit/and has flat spots at motorway speeds especially when accelerating quite hard.
Any advice help appreciated.

 

[marty_34]

the noise where sounds like the exhaust blowing sounds like its the dpf trying to regen, when that noise comes on you need to drive it down the road for 10-20 mins with the revs kept at 2000-2500 in 4th or 5th gear. once you done this and the noise quietens down that usually means the regen has completed.

if its been mapped then if you look at the countless threads on here then the dpf needs to be removed

 

[Rosskie]

mine had similar problems, flat spots under heavy load, intermittent. no codes + garage also suggested possible turbo on way out. it was the manifold actuator that was causing it, 12 quid part but manifold off to change, although might be possible to check without stripping stuff. n75 / egr and maf might be worth considering too.

 

[AndrewJB]

Well documented on here