I am pretty knowledgable about cars. I’ve had >80. Worked on everything - engines (including rotary) gearboxes, axles, bearings, steering… Need I go on?
Within a mile of driving away I had turned round and gone back. SERVICE light on, slight misfire.
Dashboard display had been turned right down to min, so the SERVICE light wasn’t obvious 'till I turned up brightness. Could get nowhere with ‘garage’ (I’ll call it a garage but remember it is a depot vente).
They signed a piece of paper I wrote out to the effect that there was a problem because the SERVICE light was on. They sent me to a garage that they use and they basically connected up a laptop to the OBD2 socket and turned off the SERVICE light.
Within 20 mins the light was back on.
… many weeks, back and forward, car basically alright, just a hint of a misfire and the SERVICE light usually on. But now always.
In the next year (purchased June 2019) did 1800km, During that time had 2 full diagnostics done at proper garages and they both showed exactly the same. 4 injectors plus associated bits and pieces…€1800 garage 1; €1400 garage2 (but s/h injectors).
How can all 4 injectors need to be replaced same time?
Then I fitted new battery. Problem gone. No SERVICE light. No ‘moteur defaut’.
4 weeks later prob returned, even worse - the auto box doesn’t change gear and the car is in ‘limp mode’.
I am adamant that the problem is very likely to be somewhere in the wiring to the fuelling system, but garages just do a diagnostic, report that 4 injectors need replacing.
I have found a report and a youtube video of an english guy who suffered exactly the same (Citroen, not identical model, but identical arrangement of wiring around the battery. He had just the same ‘diagnostic’ but traced it to a chafed wire at the back of the battery/aircleaner. He replaced wire … hey presto.
Naturally I’ve looked hard where I can for a loose connection / damaged wire… but have found nothing.