Thanks for the replies, I'll try to explain where I'm coming from. I'm certainly not an expert on any of this or a professional mechanic so bear with me. Sorry if I'm telling you something you already know.
On my M5 you can indirectly track MAF performance at WOT using an on-board "secret" menu. I'm not sure how the L/hr value translates to the M44 at this point but my OBDII scanner can also record this measurement and I'll try to develop an acceptable range after I get the car where it should be.
My experience is that once the MAF gets fouled there is little hope of correcting it. MAF cleaner will prolong MAF life if you use it from the beginning but it can't work miracles. The best recourse once it's going south is replacement. And you can replace just the sensor without the housing but it takes a little effort to track down the right part number and a good distributor. Bimmerzone.com has done this for the E39 M5 community.
You can probably expect to save at least a third and maybe as much as half the cost(compared to OE suppliers) by reusing the plastic tube. This is huge on the S62 since it has two MAFs. There's really nothing to it. You need a special security torx bit but it's as easy as removing two screws and swapping the sensor out.
Once I have a new MAF in I do try to keep them clean with CNC MAF Cleaner but this car has 157,000 and an incomplete history. I'll use cleaner to begin with but I got the car pretty cheap and I'm not 100% sure of anything maintenance-wise until I do it myself. And I trust fuel trims and scanner more than OBDII code to determine MAF health. It can be way below acceptable limits without throwing a code.
Is this even worth dealing with? Do you think I could get help from others here to track down the right P/N's? All I really need is enough people pulling thier sensor from the housing to track down the true Bosch numbers. (I wouldn't trust anything from China.) After that it's just finding a supplier.
HTH
dj |