I have a 54 plate C8, 2.2 HDI, 105 000 miles. When i first got this car at 78 000 miles I started having antipollution faults, kept clearing the faults and they would come back after a bit.My Brother in law has his own service garage so it doesnt cost me anything to have codes read and cleared. Then I had the unblock diesel filter fault, so I replaced the DPF with a new one (not citroen) and replaced the DPF pressure sensor. This fixed the problem. Now I have the antipollution fault again, the codes are. Diesel additive system, Diesel additive level, and turbo solinoid valve. The engine light stays on for 4 to 5 starts and usually goes off, I normally have power but now and then it goes into limp mode, normally if i stop and switch off for a couple of minutes and carry on the light stays on but i have power back. The additive level is fine, over three litres in the tank. the turbo code is apparantly when the car goes into limp mode. ? dunno about that one. the additive system one i dont know either. What i didnt know is that there is another ECU just for the additive system, when the codes were read for this it had a code for diesel additive pump, this code would not clear. I spoke to citroen and you cannot get just the pump you need a whole new additive tank as its built in. I did this, changed the tank put the additive fluid in and within a few miles im back in limp mode. Does anyone know of this fault? is there a way of testing the pump, or could it be a fuse? if so what one .. Any help would be appreciated.There must be someone who knows how this system works. Thanks BB.