A few tips for the same old common questions we see so have a read here 1st I am Trying to help every one with the cdti 150 and the 120 with a fee common issues to be checked I your experiencing lack of power and juddering etc
1. Egr valve sticking or stuck. Symptoms are poor acceleration and possibly black soot out the exhaust also rough idle and no power below 2000rpm
Remedy. Clean or replace egr or blank egr
Links to assist here.
Dpf blocked up (if you have one. Automatics, estates, all signums. You will have a 0.5 on your drivers door sticker where your chassis number is if you have a dpf.)
Symptoms. Are lack of power through out the rev range, poor mpg and in extreme cases engine won't start and eml on.
Remedy, try cleanin your dpf if no succeeds then either replace dpf (expensive) or remove the insides then refit and get the software removed from the ecu by means of a remap.
Vacuum boost pipes split. Symptoms are lack of turbo and poor performance. Remedy. Check pipes for splits and replace with upgraded ones or new ones from Vauxhall
Swirl linkage not on. Symptoms poor performance sometimes and also some go unnoticed. Remedy check bar and try the diy fix or in the end buy a new manifold expensive but will cure faults and increase power and mpg. To prevent future failures you can semi blank egr and vent oil system to atmosphere
No3 injector, symptoms are juddering and a slight misfire in extreme cases un driveable with eml on sometimes, remedy replace no3 injector wiring
Mods if you can make this a sticky would be a great help to everyone and save alot of repeated posts
Also if anyone else has any common faults then please add on to this in the same format with links and symptoms etc as this will help everyone thanks again