I just got failed mot from emissions. In my opinion my idling sound has changed. Does anyone know for sure, what is causing this? M62TUB44 4.4 petrol bmw engine.
Video on youtube with engine sound:

Still unsolved. Checked this morning live data and in bank 2 values are far positive. I get bank 2 last lambda error too. Catalytic conveterter failed? Bank 2 2. lambda is new genuine part.

That does sound a little rattly / tappety (if there’s such a word)!

How many miles has it done?

It may be that the chains guides are worn, or the injectors are getting very noisy - can you work out where the noise is coming from? You could put a long screwdriver against various areas and listen by putting your ear by the handle (honestly) to determine the source, albeit knowing this still may not help with your MOT failure issues. 2011 Range Rover Vogue SE 4.4 TDv8

It has around 200 000 miles, 326 000 km.
The heads, vanos, chains were done 20 000 miles ago.
The PCV system is just redone.
Checked from the livedata VANOS is good.
Car is going to a mechanic on thursday. I'm kind of curious to find out the cause for this. Checked the intake on weekend, should be good.
When looking at adaptive values, intake shouldn't be the problem in my opinion.

My engine makes some strange noises but I’m not getting any other errors but at one point I think my cats were blocked as I had a lot of engine breaking when slowing down. Mine sounds quiet when first starting apart from a start up rattle briefly but then knocks when warm but it is really hard to pinpoint where from. You could check your cats using a back pressure tester.
They can make a weird noise if the HVAs need bleeding but I would wait and see what the mechanic says.