Ok after a few weeks of research and e-mails. I came to the conclusion after reding rover ron etc sites my 03 plate TD4 had a MAf problem. I cleaned the EGR etc also cleaned the filter in black housing near injectors (forgot name)and all pipes and ducts. Still got lumpy tickkover and a little under performance. unplugged maf and it seemed stable tickover but very diesely exhaust fumes, found improvement after cleaning all filters and EGR. After investigating MAF routes I did not want to waste money on a Bosch. Rover ron has now sould out his maf side to a tuning company who never replied to my e mails regarding pierburg mafs i decided to go to the manufacturer and a supplier in germany who was helpful but unsure my idea of using the BMW pierburg would work and without the MAFAM. the new MAF from pierburg has the IAT sensor on it so doesnt need the MAFAM so i agreed to be the guinea pig and test it. The part number is 7.22684.09.0 . I fitted this tonight and the improvement was immeadiately noticeable and the tickover sweet. I will report over the next few days but after a good run it seems spot on. Hope this saves someone the pain i have been though.

how much did you pay for the maf, where did you buy it from, do you have the roverron module fitted to your vehicle ?

So this is a new BMW Pierberg with IAT sensor vs the 'old' Mercedes Pierbeg that needed the MAFAM from Rover Ron?

Which means it's a direct swap for the factory Td4 MAF but with better performance?

Sounds like a good find Ricko.

Ok 2 answers in one yes its the new pierburg maf for bmws I paid less than £100 delivered from germany no i dont have the rover ron module fitted and was very dissapointed that i never got a reply from Rover rons partners who have taken over the maf side of his business, although i am going to fit well refit a tuning box which purchased recently and kept disconnected until i had sorted MAF out Engine feels very sweet and positive I know i have cleaned almost everything else out too just in case, but the mAF made the biggest improvement. If no one finds a source for the maf here in uk or imported let me know and i will give the details but im sure they will soon be widely available possibly at BMW dealers and specialists.

Pierburg 7.22684.09.0 from Germany.

105 Euro inc tax and shipping to UK, that's £95.15

One point on this, we wouldn't know if they're selling us just the sensor, or the sensor + housing.

That is where i got mine from and its just the MAF not housing

Thanks again for the information Ricko, helps us all out.

Some info from BMW types
BMWLand: Where Power Meets Control - UK BMW - Pierburg 7.22684.09.0 Replacement MAF - My Findings
and UK supplier
Air Mass Meters airmassmeters.com

dose this maf work as a replacement for lr part MHK101130L

That seems to be what the original post is saying, it's a replacement for a Td4 Bosch maf, which is the part no. you have quoted.