Corsa diesel rough running lost power

Sounds rough! I had something similar with my Corsa, but it was a petrol one. Have you checked for any obvious air leaks in the intake manifold or around the throttle body? Might be worth a look before you start tearing things apart.

Yeah, I had a quick look for air leaks, but couldn't see anything obvious. Whereabouts were you getting the air leak? Thinking maybe it's something to do with the injectors?

Nah, wasn't an air leak in the end for me - though that's just what I thought it might be initially. You're right it could be injectors. Honestly, though with those symptoms I reckon you are better off getting it checked by a pro. Could be all sorts of things messing with the air-fuel ratio, like the mass air flow sensor or even the catalytic converter. Don't want to mess things up even more!

Thanks for the advice! Took it to a garage, and you were spot on, turned out it was a defective fuel injector. Cost 515€ to replace, but it's running sweet as a nut again. Appreciate the help!