We've recently picked up a 2005 1.6 TDCI on 90K and while it performed fine on the test drive it now seems to be throwing up a few problems. It seems to hesitate or stumble at lowish revs when maintaining speed, occasionally smokes heavily on over-run and after a longish journey the MIL came on but switched itself off over night. The MPG doesn't seem great either, its used 1/8th of a tank to do 30 miles today, mostly "A-road" 50-60mph driving with only 1 or 2 miles in town. The wife is also complaining that it stinks of soot. I have a fault code reader coming in the post so I'll see what that comes up with, but can anyone throw any light on the issues? Seems to be talk of DPF Regeneration/fluid, EGR Valves, oil catch tanks, injectors, turbos and just about every other part of the fueling/exhaust system and I'm not quite sure where to start looking! We bouhgt it from a used car dealership (the ropiest dealer I have ever bought a car from, I must admit) and used a credit card to pay for it. But I don't really want to go down the taking it back/fighting with the seller if it's a cheap or simple enough fix. Looking forward to the replies - thanks!