s80 - 53Reg - 5 -cyl D5

Fault code - generic one engine service required
balck smoke from exhaust after warmup (3-5 miles)

pipes on the engine replaced - think they are turbo/intercooler pipes
manifold off and checked
swapped EGR valve
injectors bench tested
been to volvo specialist
Spent £700 so far and still not fixed, any ideas welcome - Thanks.