159 Cruiser and
AO Silver Member
Join Date: Jul 2012
Location: United Kingdom
Your issues sounds like a normal DPF regen.
The majority of the time you will NOT get a light showing the DPF regen is in progress (this seems to come on if the DPF is badly clogged and NEEDS to be done). Most of the time the car will cope with an interrupted regen (but will start the whole process on your next drive, which will cost you more in fuel).
Next time you experience this, try and keep driving until the turbo behaves normally, and the consumption returns to normal. This will reduce the number of times it happens, and also your fuel consumption.
On my 1.9 the whole process lasts almost exactly 10mins, and you only notice it looking at the turbo guage or fuel consumption, or should I say 'did', I've cored my DPF and got a dongle which stops it!
I'd echo the thought about the EGR, normally it shuts during regen, but if it is jammed open, it will be letting some fuel back into the manifold. Is your car slightly sluggish below 2,000rpm?
159 1.9JTDM Ti and Giulietta 2.0 Veloce
ex: Punto 55s, Golf Mk5 1.4FSi, A3 (8P) Sportback 2.0TDi SE, A4 (B8) 2.0TDI S-Line, 306 HDI Meridian