2.0 GT FSi intermittent engine stutter

[Rod1609]

Hoping for some tips to cure a stuttering engine. Engine code is AXW.
Recently cured a bad oil leak between oil filter housing and block. Nightmare but all good now. 2 weeks later CEL appeared. I bought an OBD kit (not Full VCDS but it is a genuine VAG OBD device which reads codes, resets oil service light and other features and also has ability to display real time info through the data stream feature. Anyway, after plugging in I got 7 error codes, 3 of which apparently result in CEL. P1151 so replaced lambda sensor 1 bank 1, P1914 so replaced brake boost pressure sensor, P0441 so replaced valve N70. Cleared codes and all good for about a week then CEL returned. Same code, P0441 so overhauled charcoal canister. Code cleared and CEL not returned but now have intermittent engine stutter. It only appears very randomly when cruising at low speed behind slow moving traffic. 40 mph is the worst speed. No problem when accelerating or decelerating. I don't have any error codes.
Pretty sure I don't have a vacuum leak but.... I have removed inlet manifold and EGR recirc pipe a few times.
I have also replaced coolant temperature sensor, engine speed sensor and checked plugs and coil packs. I don't think its coil pack as I have no codes and problem is not apparent when accelerating.
I have checked Inlet manifold pressure sensor with integrated temp sensor via my OBD tool and sensor is fine. I have checked engine misfire on all cylinders with no misfires recorded. I have also adapted the throttle body. All fine.

I have read a few threads about EGR problems so am looking at this as the potential culprit. I have noticed when running in data stream the car does stutter sometimes at standstill when gradually increasing and decreasing engine speed. I have a feature on my OBD tool that allows some monitoring of the EGR. Car seems to stutter when 'exhaust gas air mass factor' changes from 0 to giving a reading. Any tips would be appreciated.

sorry for long thread but thought history of work over last 8 weeks would help. BTW. Car is 2005 and has covered 135,000 miles. Too old to take to VW garage and as I don't have a code anyway I don't trust VW to fix the problem.

[Rod1609]

Update - removed cover from the EGR valve assembly at the weekend as this part contains the potentiometer that is part of EGR valve flap position control. This bit can be easily removed without having to remove complete valve from engine. I rotated the female drive in the cover section a number of times back and forth. It only moves through 90 degrees. Replaced the cover and rechecked valve position and operation via VAG OBD tool. Display showed valve adapt status OK. Drove back and forth to work today (18 miles each way) and had no sign of stuttering. See how tomorrow goes but looking like problem is EGR related.

[Crasher]

There are very few of those cars around, I have only ever worked on two...

[Rod1609]

Thanks for the response Crasher, seems I am in the minority with the 2.0 fsi golf. Learnt a lot about this car since buying. Had it about 6 years. No stuttering with car again today so looks like my problems were / are if they return, with the EGR valve. Ordered a new valve so will be fitting in the near future. Hoping to keep it running for another year or so then looking potentially at a 1.4 TSFi golf. Maybe a GT model but not sure about reliability. Watching the forum with interest on thus model.

[Crasher]

One of my chaps Matt has a 2008 140 GT we sold him that a customer sold us due to the cost of repairs. They are fragile and highly strung things but both versions can be remapped to well over 200 with just a remap. The odd fact is the 140 and 170 are identical engines, the power difference is purely programming. Matt is getting on well with his but history has shown me tha engines bottom ends fails. I would get a Golf 6 GTI.