E82 118D rough idle and smoke from under the front when starting cold

[Bc420i]

My 118d has started to idle really rough feels like lts shaking. I dont feel like it gets much better when its warm. I started it cold 1 day with the drivers door open and noticed abit of blue smoke float out from under the front. It also feels to be lacking boost.

Any ideas?

Do you think it could be a boost pipe? Before i start getting into trying to work out what the problem is.

Any help is much apperciated