Rich,
Nope not getting hardly any smoke at all even under hard acceleration - never really had a problem with that.
No other problems so to speak - ticks over smoothly, performance is nice, torquey and smooth.
Not sure what the problem is.
EGR valve will deffo be sooted up though I should imagine so that is definitely worth a look. I will also have the air filter out for inspection too.
Thanks for the help and concern by the way
Pete