Apologies if this has already been covered, bit of a strange problem! My car is a 59 plate C5 tourer 1.6hdi, I've had from new. My problems began at about 108,000 miles, when the DPF fluid needed to be refilled. After my independent Citroen specialist refilled it, they had a problem clearing the fault code, and needed to replace the Eloys fluid tank, because the sensor was faulty. Afterwards all was well, but I occasionally could smell fumes in the car. Firstly I assumed it was other vehicles in front of me, but then I noticed it seemed to be when the DPF was regenerating. (I can tell when that is happening, as the MPG drops and the car feels different for a few miles). The exhaust system has been checked out, and nothing was found, and my usual Citroen specialist (who has serviced the car from new) also could not find anything, despite driving it and forcing a regeneration via diagnostics software. I am aware of the problems with injector seals on these engines, so had a look, there is no obvious leaks around them, no wet patches of fuel. The puzzling thing is that it smells ONLY when the DPF is regenerating, (every 300 miles or so), and I cannot smell it at any other time, no matter how I drive. I am beginning to think it may be the injector seals in an early stage of failure. :( The car is booked in to a main dealer tomorrow, and they agree it sounds like injector seals, and are going to change them to rule that out as a cause of the problem. I was just wondering if anybody else has had this odd problem, Thanks in advance for any help, Martyn