new egr valve fitted and still in limp mode showing up a p0401 fault code. ive pulled the pipe off the egr and there is no vacuum at all but there is a vacuum at the t piece that goes to the vacuum pump. starting to get annoyed with it now
Hi Ewanm you are not going to like this suggestion i know i would not! But i used to be on the tools as a mechanic up until 10 years ago and things have moved on so fast its worrying! My point is that you may be better off cutting your losses and going to a main dealer if you have one near you? One of the big ones if possible owned directly by Citroen.
The reason i suggest this is it sounds like you know what you are doing and will not of missed anything obvious. This would leave anyone with your fault in the dilemma you are in. The fault you describe is very often down to the egr valve so it was the first point of call, however look to see if the egr vacuum pipe goes into a small electro nematic valve down the back of the engine as these are known to play up. Otherwise unless someone comes along who has come across you problem and is willing to share the information (remember people who make a living out fixing these things very often wont let you in on their knowledge) you will just end up swopping components until you get lucky - very costly!
What ever you end up doing please let us all know how you get on and what ended up being your problem - this at least may help other people - see my injector problem posts. All the best