Afternoon all and festive cheer etc etc...

I was wondering if anyone could help? These past few days my Vectra SRi 1.9CDTi [150] has become really sluggish to the point that even in first gear it feels like there is no power and it'll limp to about 2,000 rpm and then the turbo kicks in. Also, when I turn the engine off, instead of it just quietly shutting down, it rumbles down until it stops. Further to this, the engine management light (one with the spanner) came on the dash last week for about 2 minutes but then turned off.

I'm not really sure what the problem is but for some reason, I think it might have something to do with the oil, anyone got any ideas?

Tah