Hi all I'm new on here.

I have a problem with my 2005 Volvo s40 1.6diesel it's been down on power for while now I've taken it in to my local Volvo specialist and another garage to be put on the diagnostic machine and came up with :-

glow plug fualty signal code ecm-6630
damper position faulty code ecm-0071 if they mean anything to anyone

And last week it came up with a warning light on the dash, reduced engine performance which is the ecu kicking in so there's limited damage caused.

ive done abit of research into what it might be dpf mainly? I had my dpf off the car as there was a whopping great crack all the way round where it mounts under the engine got it welded up made it abit more responsive but still down on power there's no sensors on it so I'm wondering if someone has already removed it and replaced it with a aftermarket one it's has done 133,000 after all

if anyone can shed any light on what the problem might be please let me no I'm fed up of spending money in it