2008 2.2 D4D bad diesel knock

[Mr Wagyu]

Hi guys,

I'm new here and have an 08 2.2 d4d xtr thats done 158k and love it.

I've owned it for nearly 12 months and it's always had a bit of a fuel/top end rattle. It started throwing out heavy black smoke and occasionly missing slightly on acceleration. 

It failed it's MOT on emissions and showed a P0400 code. I replaced the EGR valve, MAF sensor, fuel filter, air filter and cleaned out the choked up inlet manifold and it passed MOT with no advisories!

However, the fuel/top end knocking has got a lot worse and it's sometimes sluggish with a puff of smoke when it kicks in again. There are no errors or codes showing on my cheap reader, and the check engine/4x4/vsc is not popping up.

Before I try to take out the injectors for testing, I thought id ask if any Rav veterans on here knew of any other causes.

Any advice would be greatly appreciated.

Thanks 👍