2.0 hdi Xantia - no power, white smoke

[vincentfishing]

when I drove the car with the knackered EGR as it was seriously over fueling (lots of black smoke) and the crud from the EGR will have gone into the cylinders on its way down the exhaust.

black smoke is egr filling up with crud, white smoke is injector knackered, 2 seperate issues , dont know what mileage youve done , but injectors wear out causing nozzle leak and excessive leak off,
you could do a leak off test to check condition of your injectors,it will also show if one injector is a particular problem, its an easy test , take a few minutes and you can make up your own kit with aquarium air pipe and empty small bottles, which i used to do but when you can buy kit with all connectors etc off fleabay for about £15 may as well have it,

[trapa57]

Thank you all, especially Vincentfishing, for your responses, comments, etc the Xantia is FIXED! In the warmer days over Christmas I tried disconnecting the injectors one by one (no joy), I then swapped the air and fuel filters (no joy), checked the air piping and vac pipes (still no joy) and looked back at various FCF posts for inspiration. I reflected on the work done by the independent garage - EGR replacement, CAT clean and electro valve swap (just the one for the EGR) and decided it was worth checking the electro valve connectors, which were the other way round (blue for white, or white for blue) when checked against an engine compartment photo for an early C5 with the same 110 engine. So today I swapped the connectors just to see and bingo - power returned! It did initially kick out a lot of black smoke but then settled.
Excellent, just ready for an imminent house move.

[vincentfishing]

I'm glad you were persistant and discovered the incorrect wiring, what you dont expect from supposed proffesionals and a real needle in a hastack to find, which is why I dont go near garages, and not the sort of thing you would normally find causing your problem,
well done .

[trapa57]

Thanks, I had plenty of time to think and no immediate need to use the Xant so that made it less pressurised. I also don't use garages often but the rounded and rusty nuts securing the EGR had me beaten (so little access even with the engine mount removed and engine dropped) so I paid someone with a 4 post lift to sort it (sort of!). Still, the car has now had an early service so it's ready to go (when the salt has gone).