On a related note, cleaned out my inlet manifold the other day...
Although it doesn't look that bad, the inside was disgusting with all the soot / crap / shit the EGR has been pumping in there.
It'd also covered the MAP sensor in a layer of well... crap.
Took it for a drive, and she was very *very* smokey (even turned some of the gravel on my drive black!) for a little bit (guessing all the stuff I'd loosened being burnt off), but now seems ok - car seems to hold the boost a lot better towards the top of the rev range now though.
2 days later my hands still aren't clean!
EGR valves are a hateful invention - I'm sure they help with emissions, but I can't possible believe coating the engine with crud can possibly be good long term.