There's a number of failures that can cause your symptoms, although the warning about injectors eliminates a few of them (turbo etc.).

LPFP (either of them) failure, HPFP failure, glow plug failure (breaking off, leading to loss of compression), EGR blockage and failed injectors could all be considered possibilities. The specific error message (codes) might help narrow it down. It's unlikely to be the boost system (turbo, intercooler etc.).

The smoke you mention is usually associated with unburnt fuel, more commonly due to too much fuel being injected (injector failure) but also possibly not enough air charge (blocked EGR) although the MAP sensor will usually alert the DDE to this issue.

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Wayne
2005 BMW X5 3.0d (b 02/05)
2001 BMW F650GS Dakar (b 06/01)