Help please having problems with my e90 320d

[Hannahgemix]

Hi everyone iv got an 05 plate e90 320d for around 2 months this has been happening now been getting intermittent power loss aswell as my exhaust sounding ridiculously loud.. then il park up leave it for abit start it up and it's fine , I got it on the diagnostics and No codes came up . I took my egr valve off and manifold and they had around 1-2inchs of carbon stuck to it so I cleaned all that and put it back together thinking that itl help it but it didn't , took it to my boyfriends work ( car garage) and they're all saying to buy a new turbo for it as now Iv got blue smoke coming out , but then someone else has said they think it's my piston but I can't see either of those making my exhaust sound ridiculously loud and I don't want to waste money replacing everything when no one nos what it is. It seems to be fine when it's cold then when it gets hot then comes the power loss and ridiculous sounding exhaust and smoke , has anyone had any experience with this please?

[RUSSELLM]

Is the loud exhaust sound at the exit for the pipes, or further forward ?

If it’s further forward, I’d make sure the joint/joints are tightened.

[DuckSauce]

What did you use to scan for codes?

[sparks_190e]

Take it to another garage. To be honest, I'd try the main dealer.